affected by shingles Shingles and subsequent persisting neuralgia is much more common in older patients Pain may be triggered by touch or temperature change \200 May go on for years, be dif \201 cult to treat and have major impact on quality of life Prevent by starting antivirals within 72hr of rash (eg famciclovir) \200 See b \200\230H OW TO Treat neuralgia \200\231, p.157 for treatment Trigeminal neuralgia \200 Severe unilateral stabbing facial pain, usually V2, V3 rather t han V1 \200 Triggers include movement, temperature change, etc. \200 Time course \200 \224 years with relapse/remission \200 Depression and weight loss can result \200 Diffe rential diagnoses include temporal arteritis, toothache, parotitis and temporomandibular joint arthritis Consider neuroimaging especially if there are physical signs, ie sensory loss or other cranial nerve abnormality suggestive of secondary trigeminal neuralgia Bilateral trigeminal neuralgia suggests multiple sclerosis \200 See b \200\230HOW TO Treat neuralgia \200\231, p.157 for treatment Neuralgia can also occur with \200 Malignancy \200 Cord compression \200 Neuropathy NEUROPATHIC PAIN/NEURALGIA 157 HOW TO Treat neuralgia This can be very debilitating and treatment is dif \201 cult. There is often coexistent de pression, so always think of this and treat appropriately. Simple measures include \200 Distraction \200 Relaxation techniques \200 Allaying fea rs (usually about serious underlying pathology) \200 Acupuncture \200 Heat/cold treatme nt \200 Osteopathy/massage (to reduce associated muscle spasm) \200 Use of TENS machine s (transcutaneous nerve stimulation) \200 Support groups, eg M www.tna.org.uk Medications \200 Topical treatments, eg lidocaine, capsaicin \200 Traditional analgesic s (paracetamol, NSAIDs, opiates) although these are usually not very effective Anti-spasticity drugs, eg baclofen. Used especially in trigeminal neuralgia, they treat any muscle spasm that exacerbates the pain Mainstay of treatment is the neuromodulating drugs which may give superior pain control but often have important side effects. Examples include: Antidepressants with neuroadrenergic modulating abilities, eg amitriptyline, duloxetine. Start with a low dose and titrate up slowly. Eventual doses m ay be similar to those used in younger patients Anticonvulsants, eg gabapentin, pregabalin (postherpetic neuralgia) or carbamazepine, oxcar bazepine, valproate (trigeminal neuralgia). Start with a low dose and titrate up slowly The main side effects from these drugs are sedation and confusion, and reaching a therapeut ic dose may be limited by this problem. Other options \200 Nerve blocks or spinal stimulation, which can usually be accessed via a specialist pain clinic Surgery, eg nerve decompression, or treatment with heat or lasers. May provide relief but can result in scarring and numbness 158 CHAPTER 7 Neurology Parkinson \200\231s disease: presentation A common, idiopathic disease (prevalence 150/100 000) associated with inadequate dopamine neurotransmitter in brainstem. There is loss of ne urons and Lewy body formation in the substantia nigra. The clinical syndrome is distinct fr om Lewy Body dementia (See b \200\230Dementia and parkinsonism \200\231, p.214 for treatme nt) but there is overlap in some patho- logical and clinical \201 ndings leading to sugge stions they might be related conditions. Presentation The clinical diagnosis of Parkinson \200\231s disease is based on the UK Parki nson \200\231s disease brain bank criteria and should include: \200 Bradykinesia (slow to initiate and carry out movements, expressionless face, fatigability of repetitive movement) Plus at least one of the following: \200 Rigidity (cogwheeling = tremor superimposed on r igidity) \200 Tremor ( \200\230pin-rolling \200\231 of hands \200\224 worse at rest) \200 Postural instability Other clinical features: \200 Gait disorder (small steps) \200 Usually an asymmetrical disease \200 No pyramidal or cerebellar signs but re \202 exes are sometimes brisk \200 Non motor symptoms are common and should be asked about (se e b \200\230Non-motor symptoms of Parkinson \200\231s disease \200\231, p.158) Non-motor symptoms of Parkinson \200\231s disease \200 Depression (treat appropriately) \200 Psychosis (may relate to medications; avoid typical antipsychotics as they may worsen the motor features; atypicals such as quetiapine or olanzapine can be tried) Dementia and hallucinations can occur in late stages but drug side effects can cause simila r problems. If features suggest Lewy body dementia a trial of anticholinesterases may be wa rranted Sleep disturbance (treat restless legs, review medications, advise about driving if sudden onset sleep, daytime hypersomnolence may be treated with moda \201 nil) Falls (usually multifactorial, see b \200\230Assessment following a fall \200\231, p.104) \200 Autonomic features are generally late features, but common in older patients. They should be sought and actively managed: \200 Weight loss \200 Dysphagia \200 Constipation \200 Erectile dysfunction \200 Orthostatic hypotension \200 Excess ive sweating \200 Drooling PARKINSON \200\231S DISEASE: PRESENTATION 159 Investigations \200 Diagnosis is clinical, and once suspected should be reviewed by a Parkinson \200\231s disease specialist Trials of treatment may be done, with review of the diagnosis if there is no improvement, b ut single dose levodopa \200\230challenge \200\231 tests are no longer performed Brain imaging (eg CT) can be used to illustrate other conditions that may mimic Parkinson \200\231s disease (eg vascular disease) Specialist scans are becoming more widely used to assist diagnosis (eg consider 1 2 3 I-FP-CIT single photon emission computed tomography (SPECT), commonly kn own as DatSCAN \204 after the radiolabelled solution used) 160 CHAPTER 7 Neurology Parkinson \200\231s disease: management Should be overseen by a Parkinson \200\231s disease specialist clinic. Drugs It is not possible to identify a universal \201 rst-choice drug therapy for either early Parkinson \200\231s disease or for adjuvant drug therapy for later stages. Consider the short- and long-term bene \201 ts and risks of each treatment, along with lifestyle and clinical factors. Discussion with the patient is key. Initiation treatment is started with one of the following: Levodopa plus decarboxylase inhibitor (prevents peripheral breakdown of drug) (co-beneldopa/co-careldopa). Start low and titrate to symptoms \200 Dopamine ago nists (ropinirole, pergolide, cabergoline). Psychiatric side effects, postural hypotension and nausea often limit therapy MAOI (selegiline). The newer buccally absorbed preparation is better tolerated and useful i n swallowing dif \201 culties. These drugs have many interactions with antidepressants and should be used with care by a specialist Adjuvant treatment may be needed as the disease progresses. Firstly increase doses or add a second agent from the list already given then consider: \200 COMT inhibitor (entacapone) . Will smooth \202 uctuations in plasma levodopa concentrations. Give with each levodopa dose \200\224 sometimes will need levodop a dose decrease. Stains urine orange Amantadine \200\224 weak dopamine agonist which can reduce dyskinetic problems Apomorphine \200\224 subcutaneous (s/c) injections. Specialist treatment- rarely useful in older patients except to cover periods of nil by mouth Anticholinergics (benzhexol, orphenadrine) are mild anti-parkinsonian drugs rarely useful i n elderly patients due to severe psychiatric side effects. They do have a bene \201 cial e ffect on tremor and are possibly the drug of choice where tremor is more of a problem than bradykinesia. Surgery Ablation (eg pallidotomy) and stimulation (electrode implants) used in highly selec ted populations. Older patients often excluded due to high operative risk. Other therapeutic options \200 Patients and carers bene \201 t from regular review by a specialist doctor or nurse. Many services now have specialist Parkinson \200\231s disease n urses A course of physiotherapy can be helpful to boost mobility \200 Occupational therapy play s a vital role in aids and adaptations for disability Speech and language therapists, along with dieticians can help when swallowing becomes a problem Occasionally inpatient assessment is helpful but be aware that hospital routines can rarely match home treatment and some patients deteriorate in hospital Parkinson \200\231s UK ( M www.parkinsons.org.uk ) has plenty of information and advice for patients and carers PARKINSON \200\231S DISEASE: MANAGEMENT 161 HOW TO Manage a patient with Parkinson \200\231s disease who cannot take oral medicat ion This situation arises quite commonly in advanced disease during a hospital admission. A patient with advanced disease, admitted for another reason (eg sepsis) may miss an oral d ose of medication (eg because they are unwell, or because the drug is not immediately avail able). In some this will be well tolerated; in others there will be a rapid decline in func tion and loss of swallow, with a downward spiral unless promptly managed. Other situations in which oral medication may not be possible: Perioperatively when patient is nil by mouth \200 When an ileus or other cause makes poor drug absorption likely \200 After a stroke 2Omission of medication will (for most patien ts with Parkinson \200\231s disease) lead to a decline in function, so continuation of trea tment is key. Reducing the risk \200 Plan ahead \200\224 patients should be educated about the importa nce of taking medication on time, and always bring their own medication with them if they c ome into hospital and be encouraged to self medicate where possible If surgery is elective, then get specialist advice about medication as part of the preopera tive assessment. Aim for local or regional anesthesia if possible Have protocols in place for the urgent care of Parkinson \200\231s disease patients Ensure that wards have Parkinson \200\231s disease drugs readily available Early action \200 Use nasogastric (NG) tubes early if swallow is impaired \200 Relax ni l by mouth rules preoperatively for Parkinson \200\231s disease drugs \200 Use antiemetic s when vomiting Medication \200 Use a different preparation eg levodopa dispersible down an NG tube, buccal selegiline Use an enteral preparation eg apomorphine (subcutaneous delivery) or rotigotine (patch deli very). Advice will be needed from a specialist about doses that are equivalent to their usu al medication Further reading Brennan KA , Genever RW . ( 2010 ). Managing Parkinson \200\231s disease du ring surgery . BMJ 341 : 990 \200\223 3 . 162 CHAPTER 7 Neurology HOW TO Treat challenging symptoms in Parkinson \200\231s disease (Table 7.3 ) Table 7.3 Treatment of challenging symptoms in Parkinson \200\231s disease Possible that levodopa itself is toxic to neurons and enhances progression. In younger pati ents/milder disease start with selegiline or dopamine agonists Wearing off \200\224 progression of disease \200\224 patients require higher doses or mor e frequent dosing to produce same effect Dyskinesias Reduce levodopa dose if possible (either alone or with addition of an agonist). Add amantad ine Reduced levodopa dose more frequently (dose fractionation) or controlled release preparatio ns or add entacapone or add dopamine agonist Motor \202 uctuations with choreodystonic \200\230on \200\231 phases and freezing \200 \230off \200\231 phases. These worsen with duration of treatment Domperidone (30mg tds orally) is the best antiemetic Other drug side effects (confusion and hallucinations, constipation, urinary retention, nau sea and vomiting) are a particular problem in elderly and often limit treatment to sub-idea l levels Ensure you talk to the patient as well even if it is easier to talk to the carer. Compromis e may be necessary In general patients prefer dyskinetic side effects than \200\230off spells \200\231 \200 \224 relatives/ carers may \201 nd the opposite easier to cope with especially if patient confused or falling when \200\230on \200\231 Quantifying response to treatment is very dif \201 cult Get patients/carers to \201 ll in a 24hr chart. A formal quanti \201 ed drug trial by th erapists can be very helpful Use a rapid-acting drug (eg Madopar dispersible) in bed on waking or try a long-acting d rug last thing at night Morning stiffness End-stage disease Ultimately drug responsiveness so poor and side effects so marked that decreasing and withd rawing therapy may be appropriate. Palliative treatment and social support important Further reading NICE Parkinson \200\231s disease ( 2006 ) online: M www.nice.org.uk/cg35 . PARKINSON \200\231S DISEASE: MANAGEMENT 163 Impulse control disorders \200 De \201 ned as the failure to resist an impulse, drive or temptation to perform an act that is harmful to the person or others Tend to occur after the initiation of dopaminergic therapy in those who are susceptible, and abate with dose reduction Examples include: \200 Hypersexuality (see b \200\230Sexual function \200\231, p.528) \200 Pathological gambling \200 Compulsive buying \200 Aimless wandering \200 Repeti tive activities (eg arranging objects) \200 Dopamine dysregulation syndrome (addictive us e of dopaminergic drugs in a Parkinson \200\231s disease patient with other impulse control behaviors) 164 CHAPTER 7 Neurology Diseases masquerading as Parkinson \200\231s disease The majority of slow, stiff or shaky o lder patients on geriatric wards do not have true Parkinson \200\231s disease (Table 7.4 ). As many as 1 in 4 diagnoses of Parkinson \200\231s disease made by non-specialists are inc orrect. It is impor- tant to get the diagnosis right or you will subject patients needlessl y to the harmful side effects of medications. Coexistence of more than one syndrome can fur ther complicate diagnosis. \200 Atherosclerotic pseudo-parkinsonism/multi-infarct dementi a : Due to neurovascular damage \200\224 consider in those with stroke/TIA or with atherosclerotic ri sk factors, eg hypertension. Short-stepping, wide-based unstable gait with relative preserv ation of arm and facial movements (lower body parkinsonism). Head scan may show lacunae or white matter change Benign essential tremor : Often inherited (autosomal dominant), worse on action (spills tea from teacup), improved by alcohol and B -blockers, may have head nodd ing or vocal tremor Lewy body dementia : Lewy bodies are widely present throughout cortex not predominantly in substantia nigra as with true Parkinson \200\231s disease. Psychiatric symptoms, eg visual hallucinations tend to precede physical ones Drug-induced parkinsonism : Neuroleptics are the commonest cause but remember that prochlor perazine for dizziness and metoclopramide for nausea are also causes. Some irritable bowel treatments contain neuroleptics Other causes : Alzheimer \200\231s disease, hydrocephalus, and even severe polyarthritis can sometimes cause diagnostic confusion. Rare differential diagnoses include Wilson \200\231s disease, Pick \200\231s disease, carbon monoxide poisoning, multiple head injuries (ex-boxers) and postencephalitis or anoxic brain injury Parkinson \200\231s-plus syndromes This is a confusing array of rare disorders including: \200 Multi-system atrophy (aka Shy \200\223Drager syndrome, olivopontocerebellar atrophy) with early autonomic failure (incontinence and postural instability), ataxia, park insonism, and pyramidal signs. Cognition intact Progressive supranuclear palsy (aka Steele \200\223Richardson \200\223Olszewski disease) with up- and down-gaze palsy, axial rigidity and falls, dysarthria and dysphagia, and frontal lobe dementia DISEASES MASQUERADING AS PARKINSON \200\231S DISEASE 165 Table 7.4 Clues to distinguish Parkinson \200\231s disease True Parkinson \200\231s disease Pseudo-parkinsonism (especially atherosclerotic) Response to L-dopa Good Poor or transient Develop dopa dyskinesias Dopa dyskinesias unusual Age of onset 40 \200\22370 70 + Tremor Unilateral or asymmetrical Absent or mild Resting tremor prominent Progression Slow progression/long history Rapid progression Dementia Only at late stage Prominent or early Instability/falls Late Early and prominent Dysphonia, dysarthria or dysphagia Late Early and prominent Rare Common Other neurology (pyramidal signs, downgaze palsy, cerebellar signs) Further reading Quinn N . ( 1995 ). Parkinsonism \200\224recognition and differential diagn osis . BMJ 310 : 447 \200\223 52 . 166 CHAPTER 7 Neurology Epilepsy Primary epilepsy most commonly presents around the time of puberty but the inciden ce of new \201 ts is actually higher in the over 70s ( > 100 per 100 000) because of the increasing amount of secondary epilepsy (caused by, eg brain ischaemia, subdural haematomas , brain tumors). In addition \201 ts can be precipitated by: \200 Metabolic disturbance (eg hyponatraemi a) \200 Drugs (eg cipro \202 oxacin) \200 Infection (at any site but particularly meni ngitis/encephalitis) \200 Withdrawal from alcohol or drugs such as benzodiazepines \200 Wernicke \200\231s encephalopathy (due to thiamine de \201 ciency in malnourished, eg alcoholics) Many of these conditions are more common in older patients who also have a lower \201 t t hreshold for any given level of stimulus. Diagnosis \200 See also b \200\230Syncope and presyncope \200\231, p.108 \200 An eye w itness account is the most useful diagnostic tool \200 Look particularly for post-event c onfusion/drowsiness which is rare in cardiac syncope The classic features of prodrome, tongue-biting and incontinence are not so useful in disti nguishing cardiac from neurological syncope in older patients Remember that cerebral hypoperfusion from any cause (eg bradycardia) can cause \201 ts so epilepsy can coexist with other causes of syncope. In t hese cases treatment of the primary syncope/ hypoperfusion is more effective than anti-epil eptics. See b \200\230HOW TO Distinguish syncope and seizures \200\231, p.110 Investigations \200 Routine blood screening, CXR, and ECG to look for precipitants and differential diagnoses CT scan is vital to exclude a structural lesion \200 EEGs can be helpful when positive bu t very commonly have non- speci \201 c changes and low sensitivity, ie normal EEG does not rule out epilepsy General management \200 Ensure the patient is not taking medication that lowers the \201 t threshold (check the BNF \200\224 common examples include tricyclics, cipro \202 o xacin and phenothiazines. Think about over-the-counter drugs, eg Ginkgo biloba and stimulan ts such as cocaine) Correct any metabolic derangement (eg glucose, sodium, sepsis) \200 Advise about driving restrictions \200\224 don \200\231t assume they don \200\231t drive \200 Detect and trea t complications, eg aspiration, trauma, pressure injuries EPILEPSY 167 Driving regulations and epilepsy You have a duty to ensure that the patient informs DVLA. P atients have at least 1-year ban on driving for a \201 rst \201 t (unless a \200\230pr ovoked \201 t \200\231, eg fol- lowing brain surgery or stroke, when may be shorter perio d \200\224 individual decision). They can then reapply for license as long as they remain \201 t-free. Patients must also refrain from driving for 6 months after withdrawing epile psy medication. \200 Further information available at: M www.dvla.gov.uk Epilepsy and stroke Onset seizures (within a week, most commonly within 24hr) occur in 2 \200\2235 % of strokes . Commoner with hemorrhages, large cortical strokes and venous infarction. Consider also al cohol/drug (especially benzodi- azepine) withdrawal for early \201 ts. Long-term anticonv ulsants not usually prescribed unless \201 ts recur. After the \201 rst week stroke remains a risk factor for new epilepsy \200\224 - \201 rst year 5 % \201 t, subsequently 1.5 % annual incidence. Many such patients develop tran sient neurological worsening (Todd \200\231s paresis) or permanent worsening without CT evi dence of new stroke \200\224 in these patients it is usually worth considering long-term a nticonvulsants. Epilepsy may occur secondary to clinically \200\230silent \200\231 cerebral ischaemia and 3 % of patients with stroke have a past history of \201 ts, most occur- ring in the prece ding year. Some epilepsy experts suggest that aspirin is prescribed for new-onset seizures in an elderly patient once structural lesions have been excluded. 168 CHAPTER 7 Neurology Epilepsy: drug treatment Acute treatment \200 Start with benzodiazepines (5 \200\22310mg rectal diazepam or 2 \200\22310mg iv Diazemuls or 0.5 \200\2232mg lorazepam iv or intram uscularly (im)) If \201 ts continue consider setting up loading dose infusion of phenytoin (use a cardiac monitor) until oral medication can be taken Rarely the patient may need intubating and paralyzing to stabilize them or to allow an urgent CT scan Chronic treatment \200 Because of side effects and long duration of treatment most doctor s will resist starting anticonvulsants until after a second \201 t, especially if the dia gnosis is unclear or if there is a reversible precipitant. Presence of underlying structura l abnormality or wishing to return to driving may tip the balance in favor of treatment The choice of agent shows regional and personal variation \200 Most commonly used agents are similarly effective \200 Older agents include phenytoin, carbamazepine (both effectiv e but may be sedative) and valproate (better tolerated but plasma levels are unhelpful in monitor ing compliance or side effects) Newer agents such as lamotrigine and levetiracetam are \200\230cleaner \200\231 and increasingly used as \201 rst line All anticonvulsants have signi \201 cant side effects, eg sedation, confusion, rash, tremo r, and ataxia. Serious liver, blood and pulmonary side effects can also occur \200\224 ong oing monitoring to optimize dose and minimize side effects is necessary Many anticonvulsants interact with each other as well as other drugs and can increase toxic ity or reduce effectiveness \200\224 if in doubt consult a pharmacist. Gabapentin and preg abalin are less likely to interact with other medications and can be useful alternatives Avoid abrupt withdrawal of antiepileptics \200\224 \201 ts may be provoked \200 Partia l seizures (eg face/arm twitching) are rarely dangerous and often distress bystanders more than the patient, but they can progress to secondary generalized seizures. The same drugs c an be employed. Partial seizures often indicate structural lesions and an early CT scan is advisable Sometimes a trial of anticonvulsants in patients with recurrent unexplained collapse can be revealing Refer to an epilepsy specialist if control is proving dif \201 cult and multiple drugs are required NEUROLEPTIC MALIGNANT SYNDROME 169 Neuroleptic malignant syndrome Rare but important syndrome in patients taking neuroleptics (eg haloperidol, chlorpromazine, risperidone) with triad of: \200 Fever \200 Rigidity a nd tremor \200 Rhabdomyolysis with secondary renal failure (see b \200\230Rhabdomyolysis \200\231, p.505) 2Can be fatal (up to 30 % ) so early recognition is important. Diagnosis May arise at any time during treatment, ie patient may have recently: \200 Star ted (most common) or stopped neuroleptics \200 Increased the dose or been stable on them for a long time \200 Added a second drug, eg tricyclic antidepressant, lithium Reintroduc tion of the offending drug at a later date may not reproduce symptoms. Contributing factors such as intercurrent illness, metabolic derangement may be important in the etiology. Clinical features \200 The patient looks unwell with fever, severe lead-pipe rigidity, bradykinesia, occasionally tremor and decreased conscious level \200 Time course: onset u sually over 1 \200\2233 days, starts with rigidity/altered mental state Seizures and abnormal neurological signs can occur \200 Autonomic dysfunction causes swea ting, tachycardia, and hypertension \200 Multiorgan failure can occur, there is a leucocy tosis, and creatinine kinase levels may be over 1000IU/L Lumbar puncture, CT scan, and EEG are often required to exclude other diagnoses such as CNS infection 2The most common cause of a similar presentation is sepsis in a patient with pre-existing c erebrovascular disease. Management Stop all neuroleptics. Cooling using paracetamol, fans and damp sponging. Intrav enous \202 uids with careful monitoring of electrolytes and renal func- tion. Dantrolene (direct muscle relaxant) can speed recovery. Short- term dialysis is sometimes required. Br omocriptine is used in some cases although there is limited evidence for ef \201 cacy. Early transfer to intensive care unit may be wise \200\224 death most commonly occurs by h ypoventilation/pneumonia or renal failure. There are sometimes persisting neurological sequ elae. Serotonin syndrome A similar syndrome to neuroleptic malignant syndrome in patients taking serotonin reuptake inhibitors especially if combined with tramadol, tri- cyclic, or MAOI. P atients tend to be agitated and delirious rather than unconscious. Gastrointestinal symptom s (diarrhea/vomiting) occur. Onset may be within 2hr, resolution usually quicker than NMS. 170 CHAPTER 7 Neurology Motor neuron disease A progressive idiopathic disease with selective degeneration of motor neurons causing weakness and wasting. There is a variety of manifesta- tions depending on t he site of damage; the commonest site for lesions is in the anterior horn cells of spinal c ord (LMN), but descending motor pathway (UMN) may be affected in the corticospinal tracts, brainstem and motor cranial nuclei. 2The combination of weakness and fasciculations should always prompt consideration of motor neuron disease. \200 Onset rises steeply with age wi th peak incidence late 50s/early 60s. Very rare before age 40. Overall prevalence 7 per 100 000 but incidence 1 per 10 000 a ge 65 \200\22385 Underdiagnosed in older patients (confused with cerebrovascular disease, myasthenia, especially bulbar onset forms, cervical myelopathy, motor neuropathy, syringomyelia, and paraneoplastic syndromes) Slightly commoner in males \200 5 % will have a family history (autosomal dominant is mos t common but can be recessive or X-linked) History \200 Weakness, cramps and fatigue in limbs. Weakness usually begins in a focal ar ea and spreads to contiguous muscles, onset in upper limbs is most common Palatal and vocal cord paralysis can cause stridor, dysarthria, dysphagia, and aspiration pneumonia Paresis of respiratory muscles can cause respiratory failure (may present to chest physicians/ITU) Intellect, sensation, and continence are usually retained. Some forms associated with front otemporal dementia (<5 % ), depression common Examination \200 Look for wasting with fasciculation (LMN) especially in tongue, shoulders and legs. 2Fasciculations may be a normal \201 nding in hands and calves of old er people \200 Head drop/droop can occur \200 Brisk re \202 exes, clonus and upgoing p lantars (UMN). This is one condition that can cause absent ankle jerks and upgoing plantars Atrophy and weakness are less speci \201 c signs \200 \200\230Donald Duck \200\231 spee ch \200 Sensory changes should make you question the diagnosis Investigations \200 Creatine kinase (CK) may be elevated \200 CT, MRI, and muscle biops y are usually normal \200 Electromyography (EMG) shows denervation of muscles caused by anterior horn cell degeneration and is diagnostic MOTOR NEURON DISEASE 171 Clinical pictures Diverse presentations and rate of progression including; \200 Amyotroph ic lateral sclerosis (ALS) is the commonest form \200\224 classical picture of mixed UMN and LMN. Term used commonly in USA \200 Progressive pseudobulbar or bulbar palsy \200\224 speech and swallow predominantly affected Primary lateral sclerosis \200\224 UMNs predominantly affected \200 Progressive muscular atrophy \200\224 LMNs predominantly affected Treatment Riluzole (sodium channel blocker) 50mg bd. Prolongs survival by a few months but not function. Licensed and endorsed by NICE for amyotrophic lateral sclerosis only. Expensi ve and should be supervised by specialist. Monitor liver function and check for neutropenia if febrile illness. Supportive \200 Chest \200\224 antibiotics and physiotherapy, tracheostomy, non-invasive nocturnal ventilation (for diaphragmatic palsy, sleep apnoea) \200 Speech \200\224 early referral to speech therapy for communication aids \200 Nutrition \200\224 initially pur eed food and thickened \202 uids. Malnutrition and aspiration are indications to consider arti \201 cial feeding (see b \200\230Nutrition \200\231, p.356) Muscle spasm \200\224 baclofen, physiotherapy \200 Mobility/independence \200\224 OT fo r wheelchairs and adaptations \200 Pain/distress \200\224 opiates or benzodiazepines (bu t beware respiratory suppression) Other \200 This is devastating diagnosis to give to a patient \200\224 mean life expecta ncy is 2 \200\2235 years. Matters are often worse because there is often a considerable delay b etween symptoms and a concrete diagnosis being made (sometimes initial diagnosis may have b een incorrect). Emphasize the retention of cognition and aspects of supportive care availab le. Offer regular follow up appointments Specialist neurology/motor neuron disease nurses are available in some areas Refer to Motor Neuron Disease Association for support \200 Consider enduring power of att orney and advance directives Further reading Motor Neuron Disease Association online : M www.mndassociation.org. 172 CHAPTER 7 Neurology Peripheral neuropathies Some minor degree of sensory loss in the feet and reduced or absent ankle jerks is so common in older patients (up to 50 % of over 85 year olds) that some cla ss this as a normal ageing change, but remember: \200 Even mild, asymptomatic neuropathie s can contribute to postural instability and falls The diagnosis is often missed because of non-speci \201 c symptoms and insidious onset with slow progression Clinical features \200 There are signs of lower motor neuron weakness with wasting and lo ss of re \202 exes Sensory loss often with joint position and vibration loss before touch and pain. This is cl assically in a \200\230glove and stocking \200\231 distribution, rather than dermatomal (s ee Appendix ) Neuralgia-type pain may be present (especially diabetes and alcohol). see b \200\230HOW TO Treat neuralgia \200\231, p.157 Autonomic failure and cranial nerve involvement can also occur \200 Severe cases may affe ct respiration Classi \201 cation Try to determine if the signs are focal or generalized and whether they are predominantly sensory or motor because this can help identify the likely underlying pa thology. Further classi \201 cation by pathology (axonal or demyelinating) requires nerve conduction studies or biopsy. The commonest pattern produces widespread symmetrical sensory loss (typically glove and sto cking). This may be combined with distal muscle weakness (mixed motor and sensory neuropath y) or sometimes there is a pure motor neuropathy. Where signs are focal consider mononeurit is multiplex. Causes The causes are legion and often multiple in older patients. Idiopathic neuropathies are very common (25 % defy diagnosis in most studies). The following list is not exhaustive : \200 Idiopathic \200 Diabetes \200 Carpel tunnel syndrome \200 Paraneoplastic syn dromes (eg small cell lung cancer) \200 Alcoholism (often combined with vitamin de \201 ciency) \200 Renal failure \200 B 12 or folate de \201 ciency \200 Guillain \200\223 Barr syndrome (commonest acute onset) \200 Hypothyroidism \200 Vasculitides (eg Wegne r \200\231s granulomatosis) \200\224 actually multiple mononeuropathy Drugs (eg isoniazid, nitrofurantoin, vincristine, amiodarone) \200 Paraproteinaemias and amyloid \200 Chronic in \202 ammatory demyelinating polyradiculoneuropathy (rare autoimmune motor neuropathy) PERIPHERAL NEUROPATHIES 173 Investigations \200 Always check B 12 , glucose, TFTs, serum and urine immunoglobulins, E SR and C-reactive protein (CRP) before labeling a neuropathy idiopathic Look carefully for an occult tumor (eg breast examination and CXR) \200 Family history \200 Nerve conduction studies will con \201 rm nerve damage and distinguish demyelination from axonal damage (which sometimes helps with differential diagnosis) but th ey are not always required in straightforward cases Further specialist tests include immunology, tumor markers, lumbar puncture, molecular genetics tests, and nerve biopsy Treatment The important thing is to identify reversible causes quickly but even treat- able causes rarely respond dramatically \200\224 the aim is usually prevention of further dete rioration. Chronic in \202 ammatory polyradiculoneuropathy is treated by steroids, plasma exchange and intravenous immunoglobulin but most other chronic neuropathies have no speci \201 c treatment. Supportive and symptomatic treatment (eg appropriate footwear, analgesia, environ- mental adaptation) is important. Guillain \200\223Barr syndrome This is an acute in \202 ammatory demyelinating polyneuropathy. \200 Causes ascending pa ralysis , weakness beginning in the feet and hands and migrating towards the trunk It can cause life-threatening complications, particularly if the respiratory muscles are af fected or if there is dysfunction of the autonomic nervous system The disease is usually triggered by an acute infection This is a medical emergency which re sponds to iv immunoglobulins or plasmapheresis. These patients can deteriorate rapidly and should be managed in conjunction with specialist neurology units. Even patients who look we ll should have their vital capacity measured daily to warn of impending respiratory failure . 2The main hurdle is recognizing the diagnosis. 174 CHAPTER 7 Neurology Subdural haematoma A condition which is much more common in old age because as the brain sh rinks the veins which lie between it and the skull are much more likely to get torn followi ng trauma (even minor injury). Older people are also more likely to have falls/head injurie s and are more commonly on predis- posing drugs (eg aspirin, warfarin). Other risk factors include alcoholism, epilepsy, and haemodialysis. Features 2Subdurals frequently present with very non-speci \201 c symptoms in a frail conf used patients. A high index of suspicion is required. \200 Subdurals can occur acutely (a nd present within hours of an accident) or more slowly as the classical \200\230chronic su bdural haematoma \200\231 although this distinction doesn \200\231t help guide management \200 A history of head injury occurs in only about half \200 Common features include dro wsiness and confusion (rarely \202 uctuant), postural instability, progressive focal neurology (eg hemiparesis, unequal pupils), headach e, blurred vision Rarely transient neurology (mimicking TIA) or parkinsonism can occur \200 Some patients a re asymptomatic and large collections can be incidental \201 ndings Examine for papilloedema, focal neurology, and long tract signs Diagnosis \200 CT head scan \200\224 look for crescent-shaped haematoma compressing sulci (hypodense/black is old blood, hyperdense/white indicates recent bleeding) and midlin e shift All patients who have new UMN signs with confusion and or drowsiness should be scanned It is harder to decide when to scan a confused patient without such signs \200\224 most ag ree it is reasonable to look for other causes of acute confusion before asking for a head s can as long as the patient is being observed for any change in neurological signs or consci ous level Have a lower threshold for scanning patients on aspirin or warfarin and for those who have evidence of falls, particularly facial bruising. MRI is slightly superior and useful when C T changes are subtle (an isodense phase occurs on CT in transition between hyperdense and h ypodense changes) or very small haematomas are suspected Management Decisions are usually made in conjunction with the local neurosurgical team (alt hough in practice only about 1/3 of patients will end up having surgery). Stop aspirin and reverse warfarin therapy if possible. Observation (with or without dexamet hasone to reduce intracerebral pressure) is frequently used in: \200 Asymptomatic patients \200 Those with small bleed s who are stable/improving \200 Those not \201 t for transfer/surgery SUBDURAL HAEMATOMA 175 When conservative management is adopted, record conscious level (GCS \200\224 see b Append ix, \200\230Glasgow Coma Scale \200\231, p.696) and any focal neurology at least daily or if there is any change. Any deterioration should prompt repeat CT scan and reconsideration of surgery. Burrhole surgery is not complex and is done under local anesthetic. Recovery after surgery can be dramatic. Complications include re-bleeding and seizures. Use symptoms (especially c onscious level) not CT appearance to decide on surgery. Mortality is around 10 % \200\224 highest with depressed conscious level and bilateral haematoma. Those left with residual ne urology should receive rehabilitation as in stroke. 176 CHAPTER 7 Neurology Sleep and insomnia With increasing age less sleep is needed (approximately 1hr less than yo ung adults), circadian rhythm is less marked and sleep becomes more fragmented with greater dif \201 culty getting to sleep. Deep (stage 3 and 4) sleep is reduced but dreaming sleep /REM (rapid eye movement) is preserved. Insomnia is a symptom which correlates poorly with observed actual sleep time (ie patients who complain of poor sleep may be observed by nurses/family to sleep well while those who s leep very little do not necessarily complain). It can be very distressing and is associated with increased morbidity and mortality. Around 25 % of elderly people have chronic insomni a \200\224 even higher rates with psychiatric and medical conditions. Insomnia is a partic ular problem in an unfamiliar noisy ward environment and doctors are often under considerab le pressure to prescribe sedatives. Treatment of insomnia First ensure that underlying causes are looked for and treated: \200 Pain at night \200\224 consider using analgesics with sedative side effects eg opiates Nocturnal urinary frequency, eg due to polyuria, peripheral oedema, prostatism Comorbidities, eg orthopnoea, oesophageal re \202 ux, Parkinson \200\231s disease \200 D epression/anxiety \200\224 very common and use of an antidepressant will improve sleep much better than a hypnotic Alcohol dependence \200 Drugs \200\224 corticosteroids, omeprazole, phenytoin, amiodaron e, sulfasalazine atorvastatin, ramipril, as well as psychiatric drugs, eg paroxetine, halop eridol, and chlorpromazine can cause insomnia. B -blockers and levodopa cause nightmares The following non-pharmacological interventions (sleep hygiene) can be tried \200 Reduce or stop daytime \200\230catnapping \200\231 \200 Avoid caffeine, heavy meals and alcohol in the evening (alcohol helps to fall asleep but reduces sleep quality)