Because of this, patients do not exhibit the classic signs that accompany increased intracranial pressure such as headache, nausea, vomiting, or altered consciousness, although some studies have shown pressure elevations to occur intermittently.The exact pathogenesis is unknown, but consensus on some mechanisms include:
An imbalance exists between production and resorption of CSF. The resistance to CSF outflow is often elevated. The disease is not caused by overproduction of CSF or obstruction of CSF flow at the ventricles.The syndrome is often divided into two groups, primary (also called idiopathic) and secondary, based on cause. The underlying etiology of primary NPH has not yet been identified. Primary NPH affects adults age 40 years or older, most commonly affecting the elderly. Secondary NPH can affect persons of any age and occurs due to conditions such as subarachnoid hemorrhage, meningitis, brain surgery, brain radiation, or traumatic brain injury. Diagnosis
Patients with suspected NPH should have typical symptoms in addition to ventricular enlargement on neuroimaging. The international evidenced-based diagnostic criteria for primary NPH are:
Gradual onset after age 40 years, symptoms duration of ≥ 3–6 months, clinical evidence of gait or balance impairment, and impairment of cognition or urinary incontinence
Imaging from magnetic resonance imaging (MRI) or computed tomography (CT) is needed to demonstrate enlarged ventricles and no macroscopic obstruction to cerebrospinal fluid flow.
Pallor is a pale color of the skin that can be caused by illness, emotional shock or stress, stimulant use, or anemia, and is the result of a reduced amount of oxyhaemoglobin and may also be visible as pallor of the conjunctivae of the eyes on physical examination. Pallor is more evident on the face and palms. It can develop suddenly or gradually, depending on the cause. It is not usually clinically significant unless it is accompanied by a general pallor (pale lips, tongue, palms, mouth and other regions with mucous membranes). It is distinguished from similar presentations such as hypopigmentation (lack or loss of skin pigment) or simply a fair complexion. Causes
migraine attack or headache
excess estradiol and/or estrone
osteoporosis
emotional response, due to fear, embarrassment, grief, rage
anorexia
anemia, due to blood loss, poor nutrition, or underlying disease such as sickle cell anemia
iron deficiency
vitamin B12 deficiency
shock, a medical emergency caused by illness or injury
acute compartment syndrome
frostbite
common cold
cancer
hypoglycaemia
bradycardia
panic attack
medications
ketorolac
amphetamines
ethanol
cannabis
lead poisoning
motion sickness
heart disease
Peripheral vascular disease
hypothyroidism
hypopituitarism
scurvy
tuberculosis
sleep deprivation
pheochromocytoma
squeamishness
visceral larva migrans
Orthostatic hypotension
methyldopa
loss of appetite
Space adaptation syndrome
fibromyalgia
Buergers disease
Hypovolemia

References


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