damaged hemisphere (inability to look away) due to damage of the FEF. On the dominant side, Broca \200\231s area is responsible for the motor production of speech, whereas the nondom inant side the frontal lobe controls prosody (voice inflections with questions and statemen ts). Specific damage to Broca \200\231s area will cause stammering, hesitant speech, often with a great degree of frustration as the patient will \200\234know \200\235 what he wants to say but be unable to express himself. Posteriorly in the frontal lobe are the premotor and motor strips. These structures are the control center for voluntary face, head, neck, b ody, and limb movements of the opposite side of the body. Parietal lobe The parietal lobes are primarily sensory structures, acting as the primary in put for various somatosensory systems and providing significant networks for the interpreta tion of the incoming information. A significant portion of parietal lobe function is dedica ted to visuospatial representations \200\224maps \200\224 both of our own bodies and of our surroundings. Hence, a nondominant hemisphere parietal lobe lesion will often cause a hemi neglect syndrome, in which patients do not attend to (ignore) the contralateral side (i.e., dress- ing one half of their body, only speaking to people on one side of the room, etc.). The dominant parietal lobe, particularly Wernicke \200\231s area, is also responsible for much of the \200\234meaning \200\235 of language. Specific damage to Wernicke \200\231s are a can cause a \200\234word salad \200\235 fluent aphasia, with the patient producing string s of nonsense speech devoid of content, unaware that they neither produce nor comprehend ev en simple utterances. Temporal lobe The temporal lobes have a variety of functions including language, memory, be havior, interpretation of visual inputs, and hearing. Within the temporal lobes are the hip pocampi, responsible for consolidation of new memo- ries; damage to them (e.g., from dement ia or anoxia) causes amnesia with short-term memory loss. An epileptic focus located within the temporal lobe will often present as complex partial seizures with patients appearing c onfused and acting strangely. Occipital lobe The occipital lobes are dedicated to visual pathways. Information from the r etina is carried via the optic nerves and optic tracts to the lateral genicu- late nuclei o f the thalami. From there, the optic radiations transmit visual field information to the co ntralateral occipital lobes. Primary visual infor- mation is translated into more highly pr ocessed forms within the occipital lobes, with parallel streams of abstracted information ( color, form, motion, contrast, etc.) being passed along from the initial topographical map of the primary visual cortex. The temporal and parietal lobes assign significance to the st ructures perceived by the occipital lobes. Occipital lobe lesions cause contralateral visua l field loss (i.e., a right occipital lesion causes impaired perception of visual space to the left of fixation, through either eye; the problem is with the TV screen, not the camera s). Bilateral occipital strokes can cause complete cortical blindness (Anton \200\231s synd rome), typically with the patient being unaware of her deficit. It may present with disorie ntation and visual confabulation that may be mistaken for delirium. Isolated occipital lobe strokes are commonly \200\234missed \200\235 by patients as well as well as by providers. The patient may complain of something vaguely wrong with his vision, perhaps in the settin g of a slight orbital headache ipsilateral to the stroke. If visual fields are not examined \200\224the simplest way being a quick screen of finger movements in each quadrant distall y and finger counting in each quadrant more centrally \200\224the patient may go undiagnose d. As occipital lobe infarctions can be an early sign of a threatened basilar artery occlus ion, a missed diagnosis can be disastrous. 334 Deep nuclei: Basal ganglia, thalamus, hypothalamus These extracortical collections of gray matter lie deep within the brain. The basal ganglia predominately control motor function, w ith lesions causing extrapyramidal motor disorders such as parkinsonism (bradykinesia, rest ing tremor, masked facies), chorea (dancing/jerky movements), and athetosis (writhing). Les ions of the nearby subthalamic nucleus may cause the wildly flinging motions of hemiballism us. The anatomy of the thalamus is extremely complex, with many subnuclei, but is best know n clinically as a relay between ascending sensory pathways and the cortex. Lesions typicall y affect contralateral sensory modalities from the face and/or body, with loss of sensation or occasionally a central pain syndrome (Dejerine-Roussy syndrome). Damage to the left tha lamus sometimes produces aphasia, and to the right may produce neglect. The hypothalamus is a deep midline structure at the base of the brain, regulating a number of vital \200\234p rimitive \200\235 homeostatic functions including the biological clock, appetite mechanisms , temperature, and release of pituitary hormones. Various distinct cell populations and fun ctions are again clus- tered into numerous nuclei. y g o o r u e N l Brainstem The brainstem is expensive real estate \200\224a number of vital structures and c rucial pathways confined to a small, densely packed and complex region of anatomy. Divided into three portions \200\224the midbrain (uppermost), the pons (middle), and the medulla (l owermost) \200\224the brainstem consists of long fiber tracts descending from the brain (mo tor and modulatory) or ascending from the body (sensory), and relay circuitry to and from t he cerebellum. It also houses the various nuclei for the individual cranial nerves, as well as structures dealing with pain and its modulation, consciousness, autonomic function, nau sea, balance, and other important somatic functions. Localization in the brainstem is facil itated by identification of damaged cra- nial nerve function. For example, a process affect ing cranial nerves III or IV would occur in the midbrain, VI or VII the pons, and XI the me dulla. Because of the small size and high density of structures, nearby pathways or nuclei are nearly always affected by brainstem lesions, and thus isolated \200\234pure \200\235 c ranial neuropathies are more usually due to a more distal/periph- eral process. The trigemi nal nerve (V) has longitudinally extensive nucleus and fiber tracts, meaning that injury an ywhere from the midbrain to the upper spinal cord could result in facial sensory symptoms. 335 Cerebellum The cerebellum serves as a feedback integrator of complex movements across multi ple joints, assists in coordination of speech output, and is involved in eye movements and balance. Its role in cognition is somewhat obscure. Relatively esoteric or subtle signs of specific cerebellar lesions are beyond the scope of this chapter. In general, due to double -decussation of its prominent pathways, cerebellar lesions will cause ipsilateral incoordin a- tion (dysmetria, ataxia, impaired fine movements, or intentional tremor that worsens as the hand approaches the target). Peripheral/hemispheric lesions tend to affect limbs, and m idline lesions the trunk and balance. In cerebellar injury speech may be slowed, monotonous , jerky/arrhythmic, and/or slurred. Spinal cord anatomy As opposed to the brain, the spinal cord is organized with white mat- t er tracts coursing along the outer portions. The inner, butterfly-shaped gray matter of the spinal cord forms the anterior horn, which houses the motor neuron cell bodies that will p roject into the periphery. Important to understanding anatomic-clinical correlations is kee ping track of where specific white matter tracts decussate (cross the midline). Ultimately, all motor and sensory information will be generated or interpreted within the contralatera l brain, but whereas the corticospinal tracts (motor path- ways) and ascending dorsal colum ns (vibration and proprioceptive infor- mation) decussate within the medulla, the spinothal amic tracts (pain and temperature information) cross over within the spinal cord itself sho rtly after entering. The corticospinal tracts run along the posterolateral portions of the spinal cord. The cell bodies are located within the precentral gyrus and project their axon s down to the appropriate level of the spinal cord, crossing over to the contralateral side within the medulla. Within the spinal cord, the fibers traveling down to the legs are loca ted along the outer portions of the corticospinal tract. Thus, extramedullary spinal proces ses pushing inward (abscess, metastatic tumor) within the cervical or thoracic spine may pr es- ent with ipsilateral leg weakness. The dorsal columns that carry vibratory and proprioc eptive information are located along the posteromedial aspects of the spinal cord. Lesions of these afferent pathways cause ipsilateral symptoms. These pathways decussate within the medulla, such that lesions above the medulla cause contralateral symptoms. The dorsal colum ns have two distinct pathways, the fasciculus cuneatus and gracilis. Fibers entering the sp inal cord below T6 \200\224including from the legs \200\224travel in the fasciculus gracili s, whereas fibers at T6 and above \200\224including from the arms \200\224utilize the more medial fascicu- lus cuneatus. These are particularly vulnerable to posterior compression an d for uncertain reasons, vitamin B 12 deficiency. The spinothalamic tracts occupy the anter ior-lateral portions of the spinal cord and convey pain and temperature information from th e contralateral portion of the body to the postcentral gyrus (the primary sensory cortex). Within the spinothalamic tracts, information from the legs is carried along the outer porti ons of the tracts. The decussation of the white matter tracts occurs along the most medial anterior portion of the spinal cord, anterior to the central canal. Thus, central spinal co rd pathologies (e.g., syringomy- elia) can cause a band-like pattern of loss of pain and te mperature sensation due to disruption of the crossing spinothalamic fibers at that level. W hen a significant cervical syrinx (a dilated central canal) affects multiple levels of the central cord, the coalesced bands form a cape-like area of numbness over the shoulders and arms, often resulting in initially unnoticed burn injuries due to inability to distinguish temperature in the hands. Blood is supplied to the spinal cord via a singular anterior spin al artery and paired posterior spinal arteries. Clinically, patients with anterior spinal a rtery syndromes will have paraplegia, with loss of temperature and pain below the level of the lesion, but with sparing of vibratory sensation and proprioception. 336 Cerebral artery territories A basic knowledge of the anatomy of the blood supply of the bra in is helpful in the diagnosis and management of cerebrovascular disease. Knowledge of anat omical-vascular-functional correlation will allow a clinician to implicate a particular art ery (or arteries) without imaging. Large arterial territory ischemic strokes will cause dysfunction of a contiguous, wedge-shaped area of brain supplie d by the occluded artery (Figure 10.1). For example, a patient with symptoms that localize to both the anterior cerebral and middle cerebral arteries will quickly be assessed as havi ng likely carotid pathology, prompting a search for occlusion or dissection. A patient with significant weakness or sensory loss in the absence of any associated corti- cal findings will likely be the victim of a small, deep lacunar infarction rather than a large artery or embolic process. y g o o r u e N l Figure 10.1 Arteries and CNS territories Carotid artery Internal carotid artery occlusion may cause total infarc- tion of the anteri or two-thirds of the ipsilateral hemisphere and basal ganglia (lenticulostriate arteries). With right carotid occlusion, patients will typically have dysprosody, neglect, a right-fie ld cut, rightward eye deviation, flaccid left-sided paralysis, and profound sensory loss. M ore often, the picture is similar to an MCA occlusion (below). The cerebral arteries Three pairs of arteries leave the circle of Willis to supply the cerebral hemispheres; the anteri or, middle, and posterior cerebral arteries. The anterior and middle cerebrals are branches of the carotid arteries; the basilar artery divides into the two posterior cere- bral arte ries. These large arteries are essentially end arteries (lacking sig- nificant anastomoses) , although ischemia due to occlusion of any one of them may be reduced, if not prevented, b y retrograde supply from meningeal vessels. 337 Anterior cerebral artery (a, above): Supplies the frontal and medial part of the cerebral h emispheres (including the \200\234leg \200\235 area of the homunculus). Occlusion may caus e a weak, numb contralateral leg similar, if milder, arm symptom. The face is generally spared. Bilateral infarction may lead to an akinetic mute state due to damage to the cingul ate gyri and is also a rare cause of paraplegia. Sometimes both arteries originate from a s ingle carotid. Middle cerebral artery (m): Supplies the lateral (external) part of each hem isphere, including the face and arm areas of the homunculus. Occlusion may cause contralate ral hemiplegia, hemisensory loss mainly of face and arm, contralateral homonymous hemianopi a due to involvement of the optic radiation, cognitive change including aphasia if the domi nant hemisphere is affected, and visuospatial disturbance (e.g., cannot dress, neglect, get s lost) with nondominant lesions. (Continued) Figure 10.1 (Continued) Posterior cerebral artery (p): Supplies the occipital lobe. Occlusion causes contralateral homonymous hemianopia. Vertebrobasilar circulation: Supplies the cerebellum, brainstem (wit h the cranial nerve nuclei), and occipital lobes. Depending on specific involve- ment, occl usion may cause hemianopia, cortical blindness (bilaterally occipital), diplopia, vertigo, nystagmus, hemi- or quadriplegia, unilateral or bilateral sensory symptoms, cerebellar symp toms, hiccups, dysarthria, dysphagia, and coma. Infarctions of the brainstem can produce va rious eponymous syndromes, a common one being Wallenberg \200\231s or lateral medullary syn drome (occlusion of a posterior inferior cerebellar artery, sometimes due to vertebral arte ry occlusion). Infarction of the lateral medulla and inferior surface of the cerebellum cau ses vertigo with vomit- ing, dysphagia, nystagmus, ipsilateral ataxia, paralysis of the sof t palate, ipsilateral Horner \200\231s syndrome, a crossed pattern of sensory loss (analge- sia to pinprick on ipsilateral face and contralateral trunk and limbs), and, interestingly , hiccups. Subclavian steal syndrome: Subclavian artery stenosis proximal to the ver- tebra l artery may cause blood to be \200\234stolen \200\235 by retrograde flow down the vertebr al artery, down into the arm, causing brainstem ischemia after exertion. Suspect if the blo od pressure (BP) in the arms differs by >20 mm Hg. Figure 10.2 Cerebral arterial anatomy 338 Cerebral blood supply The brain is supplied by the two internal carotid arteries and the ba silar artery (formed by the joining of the two vertebral arteries). These three vessels fee d into an anastomotic ring at the base of the brain called the Circle of Willis (Figure 10. 2). This arrangement may lessen the effects of occlusion of any single feeder vessel by all owing collateral supply from unaf- fected vessels. The anatomy of the Circle of Willis is, however, highly vari- able and is \200\234incomplete \200\235 in many people (e.g., missin g one or more of the communicating arteries) and thus may in some cases be unable to provid e much in the way of redundancy. In other variations, the typically posterior arteries may de rive from the anterior supply (e.g., the posterior cerebral arteries originating from the c arotid rather than the basilar). Collateral supply from other vessels in the neck may also mitigate occlusions of feeder vessels (e.g., occlusion of the internal carotid in the neck may not cause a large infarction if flow from the external carotid artery enters the Circle of Willis via the facial artery and its anastomosis with the ophthalmic artery). y g o o r u e N l Peripheral nerves, myotomes, and dermatomes The peripheral nervous system is made up of sen sory and motor nerves that form from the roots emerging from the dorsal and anterior horns of the spinal cord respectively. Some nerves are pure motor (e.g., suboc- cipital), some pu re sensory (e.g., sural), but most are mixed. Pathologies can affect the nerve root, plexus , or peripheral nerve itself. Thus, identify- ing the root and the nerve that is responsibl e for each area of sensation and each muscle is vital for localizing peripheral nervous sys tem patholo- gies. Table 10.5 summarizes motor nerve root innervation (myotomes) and indivi dual peripheral nerve innervation patterns of selected muscles. When trying to discern a C7 lesion from a radial nerve lesion, an examiner could test muscles innervated by the radial nerve, but not C7, such as the brachioradialis. Also, an examiner could test C7 innervated muscles that are not innervated by the radial nerve, such as the flexor carpi radialis, wh ich is innervated by the median nerve. Table 10.5 Motor testing: Roots, nerves, muscles, actions Nerve root C3, 4 C5, 6 Muscle Trapezius Serratus anterior Test by asking the patient to: Shrug shoulder (via accessory nerve) Push arm forward agains t resistance; look for winging of the scapula, if weak 339 C 5 , 6 Pectoralis major (p. major) clavicular head P. major sterno- costal head Supraspinatus Infr aspinatus Latissimus dorsi Biceps Deltoid Adduct arm from above horizontal and push it forward C6, 7 , 8 Adduct arm below horizontal C 5 , 6 C 5 , 6 C6, 7 , 8 C5, 6 C 5 , 6 Abduct arm the first 15 degrees Externally rotate arm, elbow at side Adduct arm from horizo ntal position Flex supinated forearm Abduct arm between 15 and 90 degrees Radial nerve C6, 7 , 8 C5, 6 Triceps Brachioradialis Extend elbow against resistance Flex elbow with forearm half way between pronation and supination C5, 6 Extensor carpi Extend wrist to radial side with radialis longus fingers extended C6, 7 Supinator Arm by side, resist hand pronation (Continued) Table 10.5 (Continued) Nerve root C 7 , 8 Muscle Extensor digitorum Keep fingers extended at metacarpo- Test by asking the patient to: phalangeal (MCP) joint Extend wrist to ulnar side C 7 , 8 Extensor carpi ulnaris C 7 , 8 Abductor pollicis Abduct thumb at 90 degrees to palm longus C 7 , 8 Extensor pollicis Extend thumb at MCP joint brevis C 7 , 8 Extensor pollicis Resist thumb flexion at interphalan- longus geal (IP) joint Median nerve C6, 7 Pronator teres Maintain arm pronation against resistance C6, 7 C7, 8 , T1 Flexor carpi radialis Flex wrist toward radial side Flexor digitorum superficialis Resist extension at proximal interpha- langeal (PIP) joint (with proximal phalanx fixed by the examiner) C7, 8 Flexor digitorum profundus I & II Resist extension at index distal interphalangeal (DIP) joint of index finger C7, 8 , T1 Flexor pollicis Resist thumb extension at interpha- longus langeal joint (fix proximal phalanx) Abduct thumb (nail at 90 degrees to C8, T1 Abductor pollicis brevis palm) C8, T1 Opponens pollicis Thumb touches base of fifth fingertip (nail parallel to palm) C8, T1 Lumbrical/interos- seus (median & ulnar nerves) Extend PIP joint against resis- tance with MCP joint held hyperextended 340 Ulnar nerve C7, 8 , T1 Flexor carpi ulnaris Flex wrist to ulnar side; observe tendon C7, C 8 Flexor digitorum profundus III and IV Resist extension of distal phalanx of fifth finger while you fix its middle phalanx C8, T1 Dorsal interossei Finger abduction: Cannot cross the middle over the index finger (tests index finger adduction too) C8, T1 Palmar interossei Finger adduction: Pull apart a sheet of paper held between middle and ring finger DIP joint s of both hands; the paper moves on the weaker side C8, T1 Adductor pollicis Adduct thumb (nail at 90 degrees to palm) C8, T1 Abductor digiti Abduct little finger minimi C8, T1 Flexor digiti minimi Flex the little finger at MCP joint (Continued) y g o o r u e N Table 10.5 (Continued) l Lower limb Nerve root L 4 , 5 , S1 Muscle Gluteus medius & minimus (superior gluteal nerve) Activity to test: Internal rotation at hip, hip abduction L5, S1, 2 Gluteus maximus (inferior gluteal nerve) Extension at hip (lie prone) L 2 , 3 , 4 Adductors (obtu- rator nerve) Adduct leg against resistance Femoral nerve L 1, 2, 3 Iliopsoas (also sup- plied via upper lumbar spinal nerves) Quadriceps femoris Flex hip against resistance with knee flexed and lower leg supported: Patient lies on back L2, 3 , 4 Extend at the knee against resistance; start with the knee flexed Obturator nerve L 2 , 3 , 4 Inferior gluteal nerve L 5 , S 1 , S2 Hip adductors Adduct the leg against resistance Gluteus maximus Hip extension ( \200\234bury heel into the bed \200\235) with knee in extension Superficial gluteal nerve L 4 , 5 , S1 Gluteus medius & Abduction and internal hip rotation with leg flexed at hip and knee minimus Sciatic: common peroneal* and tibial** nerves *L 4 , 5 *L 5 , S1 Tibialis anterior Extensor digitorum Dorsiflex ankle Dorsiflex toes against resistance 341 longus L 5 , S1 Extensor hallucis Dorsiflex hallux against resistance longus L5, S1 Peroneus longus & Evert foot against resistance brevis L5, S1 Extensor digitorum Dorsiflex proximal phalanges of toes brevis L5, S1 , 2 Hamstrings **L4, 5 **S1, 2 **L5, S 1 , 2 Flex the knee against resistance Invert the plantarflexed foot Plantarflex ankle or stand o n tiptoe Flex terminal joints of the toes Tibialis posterior Gastrocnemius Flexor digitorum longus Small muscles of foot Make the sole of the foot into a cup S1, 2 Quick screening test for muscle power Shoulder Abduction C5 Hip Flexion Adduction Extension Flexion L1 \200\223L2 L2 \200\2233 L5 \200\223S1 L5 \200\223S1 Adduction C5 \200\223C7 C5 \200\223C6 Flexion C7 Extension Elbow Knee (Continued) Table 10.5 (Continued) Quick screening test for muscle power Wrist Flexion Extension Flexion Extension Abduction C7 \200\2238 C7 C8 C7 T1 L3 \200\223L4 L4 L5 \200\223S1 Eversion Plantarflexion S1 \200\223S2 Big toe extension Extension Ankle Dorsiflexion Fingers L5 Toe The segment of skin innervated by a particular nerve root is known as a dermatome ; cutaneo us nerves derive from portions of multiple roots. Although nerve root/dermatome distributio ns tend to be somewhat ill-defined and may overlap, cutaneous nerve distributions tend to b e dis- tinctly marginated, crossing multiple dermatomes. Figures 10.3 and 10.4 illustrate t he cutaneous innervation of the anterior and posterior skin sur- face, respectively. 342 y g o o r u e N Figure 10.3 Dermatomes and cutaneous nerves l Great auricular, C.2, C.3 S.2, 3 343 Figure 10.4 C.2, C.3 C.2, C.3 \200\223 C.3, C.4 344 Headache Every day, thousands of patients visit doctors complaining of headache. It is the top neurological chief complaint in primary care settings, a top-five emergency room chief complaint, and the most common reason for neuro- logical referral. A variety of pathologies can cause cephalalgia (head pain), most of which are benign or primary headache syndromes (e.g., migraine, tension-type), but that occasionally may be the harbinger of impending cat astrophe (e.g., subarachnoid hemorrhage, meningitis). Recognizing com- mon syndromes as wel l as indications for evaluating patients for potentially more serious conditions is extreme ly important for every physician. At first cut, the goal of assessing a patient with a head ache complaint should focus on distinguishing a secondary headache \200\224nociceptive pain as a symp- tom of an underlying identifiable pathology \200\224from a primary headache, on e of the more benign, idiopathic headache syndromes . There are a variety of ways to approa ch the differential diagnosis for head- ache. \200\234Red flags \200\235 serve to triage p atients for further or expedited workup, increasing the likelihood that the patient is suff ering from a dangerous or treatable secondary headache. A useful red flag mnemonic \200\224 HPAIN (see Table 10.6) \200\224is given. The temporal pattern ( \200\234P \200\235of HPAIN) of the head- ache is particularly salient. Sudden onset with rapid time to peak intensity ( \200\234thunderclap \200\235 \200\224see discussion and differential under subarachnoid h emor- rhage), first, worst, or unusual headaches require more urgent triage; a stable patte rn of recurring headaches with complete return to baseline each time is seldom a cause for alarm. A brief list of selected headache syndromes based on temporal pattern of presentatio n is given in Table 10.7. The individual headaches will be discussed below. Migraine, the m ost clini- cally prevalent and important, will be discussed separately. y g o o r u e N l Acute single episode Meningitis, encephalitis, subarachnoid hemorrhage: If the headache is acute, severe, felt over most of the head and accompanied by meningeal irritation (neck sti ffness) drowsiness, you must think of meningitis, encephalitis, or a subarachnoid hemorr hage. Emergent head imagining with a computed tomography (CT) scan and possible LP is indic ated, possibly with follow up MRI/A/V if unrevealing. After head injury: Headache is common after trauma. It may be at the site of trauma or be more generalized. It typically lasts a pproximately 2 wks and is often resistant to analgesia. Bear in mind subdural or epidural h ema- toma. Worrisome are any drowsiness or any focal neurological signs or symptoms. Chroni c post-traumatic headaches may respond to treatment for chronic migraine, and presentation may be complicated by litigation, worker \200\231s comp, etc. Paradoxically, they are more likely to occur after minor 345 Table 10.6 HPAIN: Identifying headache \200\234red flags \200\235 H ost: Particular patient vulnerabilities. Older, immunocompromised or suppressed, cancer, autoimmune disease P attern: Sudden and severe ( \200\234thunderclap \200\235), first, wors t, new onset, steady progression, change in previously stable pattern A ssociated systemic symptoms: Fever, stiff neck, weight loss, rash, etc. I ncreased by, provoked by, or worsene d by: Valsalva, upright posture, exertion, sleeping N eurological symptoms or signs: Seizur e, numbness, weakness, unsteadi- ness, impaired or double vision Table 10.7 Differential diagnosis for selected headache syndromes based on presentation Acute single episode Meningitis Encephalitis Fever, photophobia, stiff neck, rash, coma Fever, odd behavior, seizures or change in consciousness Subarachnoid Sinusitis Sudden headache stiff neck loss of consciousness Pressure, tender face + coryza + ano smia + postna- sal drip/cough; nearly all cases of isolated recur- ring \200\234sinus \200 \235 headaches are misdiagnosed migraines. Cuts/bruises, transient or ongoing \206\223 con sciousness, Head injury lucid interval, amnesia Spontaneous intracranial hypotension (SIH) Sudden onset, improves with lying flat, worsens when upright. Acute recurrent attacks Migraine Any pre-attack visual or sensory aura (25% of migraineurs). Sensitivity to light, noise, or move- ment; nausea; throbbing or pounding qua lity; uni- lateral or bilateral; typically last hours to a few days Typically repeated epis odes (1 \200\2235+/d) of excruciating pain in one periorbital region, with ipsilateral eye and nose symptoms, lasting for 30 mins to 2 h, active for 8 wks followed by weeks of remi ssion Cluster headache Glaucoma Rarely. Red eye; sees haloes, fixed big oval pupil; \206\223 acuity Acute recurrent attacks Subacute onset Giant cell arteritis Tender scalp; >50 yrs; vision c hanges, systemic com- plaints, very elevated erythrocyte sedimentation rate (ESR) or c-reac tive protein (CRP) Chronic headache (pain for >15 d/month for >3 months) Chronic 346 \200\234A tight band round my head, \200\235 otherwise fairly tension-type headache Chronically featureless Pseudotumor cerebri/idiopathic intracranial hyper- tension (IIH), or symptomatic ICP elevat ion due to hydrocephalus, mass lesion, venous throm- bosis. Worse overnight or upon waking; blurred vision, papilledema, and eventual transient visual obscurations; may have pulsatil e tinnitus (heart- beat in ears); focal signs if due to a lesion elevated intrac- ranial pressure (ICP) Rebound headache Analgesic overuse (>2 d/wk on average, particu- larly with barbiturates or narcotics) in a known migraineur; develops over months Chronic migraine aka transformed migraine Continuous or near continuous underlying smolder- ing headache, spiking at times to full-bl own migraine, in a known migraineur; typically develops over many months to years. Exacerba tions respond at times to migraine-specific treatments rather than severe injury. Rarely are they the result of spinal fluid leaks, accompanying u pper neck trauma, or nerve injury. Sinusitis: Presents with dull, constant, aching pressure over the affected frontal or maxillary sinus, with tender overlying skin postnasal drip . Pain is typically a minor feature of sinus infection. Ethmoid or sphenoid sinus pain is f elt deep in the midline at the root of the nose. Pain worsened by bending over. Often accom panied by coryza; symptoms may last 1 \200\2232 wks. Endoscopy or sinus CT scan may verify diagnosis. Role of antibiotics is controversial as most cases are viral. Acute glaucoma: Mo stly observed in elderly, far-sighted people. Constant, aching pain develops rapidly around one eye and radiates to the forehead. Symptoms: Markedly reduced vision in affected eye, n ausea, and vomit- ing. Signs: Red, congested eye; cloudy cornea; dilated, non-responsive pu pil. Attacks may be precipitated by sitting in the dark, such as at the movies; by dilating eye-drops; or emotional upset. Seek expert help immediately. If delay in treatment of >1 h is likely, start IV acetazolamide (500 mg over several minutes). y g o o r u e N l Recurrent acute attacks of headache Cluster headache: Pain occurs up to seven times every 2 4 h, each episode lasting 15 \200\223160 min. Active cluster periods typically last 4 \200 \22312 wks and are followed by pain-free periods of months or even 1 \200\2232 yrs before a nother cluster begins. Sometimes there are no remissions. Men outnumber women 3 to 1. Class ically, patients are agitated, rocking, or writhing in pain, unlike migraineurs who usually remain quite still and quiet during a headache. May become irrational and injure self or o thers. Suicide risk. Image all cluster-like headache patients with MRI, refer to neurologis t or headache subspecialist. Symptoms: Rapid onset severe pain around one eye, which may be come watery and bloodshot with lid swelling, lacrimation, facial flushing, and rhi- norrhea . Miosis ptosis (20% attacks), remaining permanent in 5%. Pain is strictly unilateral an d almost always side-locked. Treatment: Acute attack: 100% O 2 (10 \200\22315 L/min for 20 min) often helps, or sumatriptan SC 6 mg at attack \200\231s onset. IV or nasal DHE, nasal triptans may be helpful, but oral drugs are typically too slow to act. Indomethacin and int ranasal lidocaine are also effective abortive agents. Preventives (NB: Scant quality eviden ce in litera- ture): Verapamil up to 960 mg/day (checking ECGs at 480 mg and above); lithiu m; topiramate; divalproex. 2 \200\2234-wk steroid taper and ipsilateral greater occipital n erve block with steroids and local anesthetic for bridge therapy. Trigeminal neuralgia (TN) : Paroxysms of intense, unilateral stabbing facial pain, lasting seconds, typically in V2 ( maxillary) and/or V3 (mandibular) distribution. The face may twist with pain (hence the mon iker, tic douloureux ). Pain may recur many times a day and night and can often be triggere d by touching the skin of the affected area, by washing, shaving, eating, or talking. TN of ten pres- ents in older men, with most cases resulting from microvascular compres- sion of the trigeminal nerve roots as they exit the brainstem but can occur due to other mass lesio ns and multiple sclerosis (MS) as well (consider this especially in a younger, female patie nt). All patients should be imaged with a high-resolution contrast-enhanced brain MRI, with heavily T2-weighted thin cuts through the brainstem and trigeminal nerves to assess for ca usative lesions. Treatment : Carbamazepine (start at 100 mg/12 h PO; max 400 mg/6 h; oxcarb azepine working up to as high as 900 mg bid; lamotrigine (slow to titrate but well-tolerate d); phenytoin 200 \200\223400 mg/24 h; or gabapentin up to 1,800 mg tid. Baclofen may work rapidly for rescue, and, in extreme cases, IV anticonvulsants may be required. The conditio n is often surgi- cally curable; after imaging, we recommend referring all cases to neuro- surgery early to discuss options if medications fail or cause intolerable side 347 effects. Interventions may be directed at the peripheral nerve, the trigeminal ganglion (rh izotomy with radiation, radiofrequency, or glycerol lesioning), or the nerve root with surg ical microvascular decompression to separate anomalous vessels from the nerve. Headaches of subacute onset Giant cell arteritis: Exclude in all patients >50 presenting wi th a headache that has lasted a few weeks. Look for tender, thickened, pulseless temporal a rteries with an extremely elevated ESR. Ask about jaw claudication during eating (specific, not sensitive), systemic symptoms (malaise, sweats, muscle aches, weakness of limb girdles /polymyalgia rheumatica), and episodes of vision loss (amaurosis fugax). Prompt diagnosis a nd immediate treatment with steroids (starting at 60 \200\22380 mg of PO prednisone) are es sential for avoiding blindness or potential strokes. The temporal arteries should be biopsi ed to confirm the diagnosis; start steroids first to prevent compli- cations, then ensure t hat adequate 4 cm+ biopsies, ideally bilaterally, are performed within 10 d. Chronic headaches Raised ICP: Headache is a complaint of 50% patients with \206\221 ICP, whether idiopathic intracranial hypertension (IIH, aka pseudotumor cerebri or \200\234benig n \200\235 intracranial hypertension) or due to hydrocephalus or other mass lesion. Althoug h variable in nature, headaches are characteristically present on waking or may awaken the patient overnight. They are gener- ally not severe and are worse lying down. If accompanied by other signs of \206\221 ICP, such as vomiting, papilledema, seizures, focal deficits, or men- tal status change, admit the patient urgently for diagnostic imaging. Any space-occ upying lesion (neoplasm, abscess, subdural hematoma) may pres- ent in this way, as may IIH, or cerebral venous thrombosis. Lumbar punc- ture is the diagnostic test of choice in patie nts with unremarkable imaging ; cerebellar herniation may be risked if there is obstructive hydrocephalus or mass lesion. Classically, patients with IIH are overweight women of child -bearing age (20-fold elevated risk over general population, but still 100-fold less com- m on than chronic migraine in this group) who have constant dull head pain and vision changes . Think of this diagnosis in those presenting as if with a mass (headache, \206\221 ICP, a nd papilledema) when no mass is found and when there is no venous occlusion. Consciousness and cognition are preserved. Opening pressure during LP is elevated. Cause : Unknown. Rule out elevated ICP secondary to venous sinus thrombosis (contrast-enhanced MRV, CTV, or angio graphy are the best studies) or drugs (e.g., tetracycline, minocy- cline, nitrofurantoin, v itamin A, isotretinoin, danazol, and somatropin). Treatment : Treatment should be geared to ward preserving vision rather than headache. Refer all suspected cases of ICP elevation ear ly and often to ophthalmology; urgent optic nerve sheath fenestration or neurosurgi- cal tr eatment may prevent permanent blindness. Ophthalmological workup should include funduscopy (ideally with photo documentation), perimetry, and color vision testing. Urgent and even se rial lumbar punctures (LPs) (with measurement of the opening pressure) with drainage of 20+ cc of cerebrospinal fluid (CSF) may be indicated in patients with worsening symp- toms. Ac etazolamide is the mainstay of medical treatment; consider loop diuretics and advise weight loss in all patients. High-dose topiramate may be useful in causing both weight loss and C SF pressure-lowering effects. Surgical shunting or even venous stenting may be indicated in specific cases. Prognosis: Often self-limiting. Permanent significant visual loss in 10% ( i.e., not so benign), higher if not treated. 348 Intracranial hypotension: An internal leak of CSF, whether iatrogenic (LP, surgery, overshu nting), due to trauma, or spontaneous (SIH), tends to pres- ent with a postural headache, w orsening when upright and improving when recumbent, particularly with prolonged sleep. Some SIH patients experi- ence thunderclap headache at onset. When mild, the disorder presents as a daily recurring headache absent in the morning that comes on gradually and then worsen s toward the end of the day. Valsalva or straining, such as during bouts of cough may exace rbate symptoms, and meningeal irritation may cause increased pain during jarring motions. R arely, there are associ- ated cranial neuropathies, ataxia, a frontotemporal dementia-like picture, or even a reduced level of consciousness. Patients with certain connective tissue or genetic disorders that cause weakening or outpouchings of the spinal meninges may be par ticularly susceptible (Ehlers-Danlos, Marfan \200\231s, neurofibromatosis). Characteristic imaging findings on contrast brain MRI include signs of downward displacement of brain stru ctures ( \200\234sag \200\235), includ- ing the cerebellar tonsils (resembling Chiari I mal formation), engorgement of vascular structures such as the pituitary and venous sinuses, an d avid enhancement of the pachymeninges (dura), which in coronal cross-section through the posterior fossa may resemble a Mercedes-Benz symbol drawn in white. Opening pressure on rec umbent LP is often <7 cm H 2 O, but may be normal. Leaks can be localized by a variety of t echniques. In skull base leaks, CT may reveal fluid in the sinuses, and collection of nasal discharge will test positive for 2 -transferrin, found only in CSF and endolymph but no t in mucous. Spinal leaks, often at the cervical-thoracic junction, at dilated nerve root s heaths/Tarlov cysts, or due to osteophytes, can be local- ized by CT myelography, CSF radio cisternography (include nasal pledgets if skull base leak is suspected), and noninvasively by high-resolution heavily T2-weighted MRI. SIH is well worth knowing about \200\224it may be as com- mon as subarachnoid hemorrhage, is commonly missed, can be extremely disabling, and is entirely curable through interventional procedures such as empiric or radiographical ly directed epidural blood patch or fibrin gluing. y g o o r u e N l