(17) Nervous System Reds Flashcards
cherry red color suggests ?
carbon monoxide poisoning
Diabetic patients with small-fiber
neuropathy report
whereas those with large-fiber neuropathy experience
sharp, burning, or shooting foot pain
numbness and tingling or even
no sensation at all.
Primary headaches include
secondary headaches arise from
migraine, tension, cluster, and trigeminal autonomic cephalagias
underlying structural, systemic, or infectious causes and may be life threatening
Subarachnoid hemorrhage classically
presents as
Severe headache and stiff neck accompany
Dull headache increased by coughing and sneezing, especially when recurring in the same location, occurs in
“the worst headache of my
life” with instantaneous onset
meningitis
mass lesions from brain tumors or abscess
Migraine headache is often preceded by
an aura or prodrome, and is highly likely
if three of the five “POUND” features are
present: Pulsatile or throbbing; Oneday
duration, or lasts 4 to 72 hours if
untreated; Unilateral; Nausea or vomiting;
Disabling or intensity causing interruption
of daily activity
a
Feeling light-headed, weak in the legs, or about to faint points to presyncope from vasovagal stimulation, orthostatic hypotension, arrhythmia, or side effects from blood pressure and other medications
a
Vertigo often reflects vestibular disease,
usually from peripheral causes
in the inner ear such as benign positional
vertigo, labyrinthitis, or Ménière
disease
a
Ataxia, diplopia, and dysarthria are suspicious for vertebrobasilar TIA or stroke.25–30 Also consider posterior fossa tumor and migraine with brainstem aura.
a
Abrupt onset of motor and sensory deficits occurs in TIA and stroke.25–30 Progressive subacute onset of lower extremity weakness suggests Guillain–Barré syndrome.31 Chronic, more gradual, onset of lower extremity weakness occurs in primary and metastatic spinal cord tumors
a
Focal or asymmetric weakness has both central (ischemic, thrombotic, or mass lesions) and peripheral causes ranging from nerve injury to the neuromuscular junction disorders to myopathies
a
Proximal limb weakness, when symmetric with intact sensation, occurs in myopathies from alcohol, drugs like glucocorticoids, and inflammatory muscle disorders like polymyositis and dermatomyositis. In the neuromuscular junction disorder myasthenia gravis, there is proximal typically asymmetric weakness that gets worse with effort (fatigability), often with associated bulbar symptoms such as diplopia, ptosis, dysarthria, and dysphagia
a
Bilateral predominantly distal weakness,
often with sensory loss, suggests
a polyneuropathy, as in diabetes.
a
Sensory changes can arise at several levels: local nerve compression or “entrapment,” seen in hand numbness in distributions specific to the median, ulnar, or radial nerve; nerve root compression with dermatomal sensory loss from vertebral bone spurs or herniated discs; or central lesions from stroke or multiple sclerosis.
a
Burning pain occurs in painful sensory
neuropathies from conditions like
diabetes
a
A pattern of stocking, then glove, sensory
loss occurs in polyneuropathies,
especially from diabetes; multiple
patchy areas of sensory loss in different
limbs suggest mononeuritis multiplex,
seen in diabetes and rheumatoid
arthritis
a
Causes include seizures, “neurocardiogenic”
conditions such as vasovagal
syncope, postural tachycardia syndrome,
carotid sinus syncope, and
orthostatic hypotension, and cardiac
disease causing arrhythmias, especially
ventricular tachycardia and
bradyarrhythmias.37 Stroke or subarachnoid
hemorrhage are unlikely
causes of syncope unless both hemispheres
are affected
a
In vasovagal syncope, the most common cause of syncope, look for the prodrome of nausea, diaphoresis, and pallor triggered by a fearful or unpleasant event, then vagally mediated hypotension, often with slow onset and offset. In syncope from arrhythmias, onset and offset are often sudden, reflecting loss and recovery of cerebral perfusion
a
Common causes of acute symptomatic seizures include: head trauma; alcohol, cocaine, and other drugs; withdrawal from alcohol, benzodiazepines, and barbiturates; metabolic insults from low or high glucose or low calcium or sodium; acute stroke; and meningitis or encephalitis
a
Tonic–clonic motor activity, bladder or bowel incontinence, and postictal state characterize generalized seizures. Unlike syncope, tongue biting or bruising of limbs may occur
a
Epilepsy is more common in infants and
older adults. The baseline neurologic
examination is frequently normal
a
Generalized epilepsy syndromes usually
begin in childhood or adolescence;
adult-onset seizures are
usually partial
a
Low-frequency unilateral resting tremor, rigidity, and bradykinesia typify Parkinson disease.43,44 Essential tremors are high-frequency, bilateral, upper extremity tremors that occur with both limb movement and sustained posture and subside when the limb is relaxed; head, voice, and leg tremor may also be present
a
Reversible causes of restless legs
syndrome include pregnancy, renal
disease, and iron deficiency
a
The AHA/ASA report cites the wellvalidated ABCD2 scoring system for predicting ischemic stroke within 2, 7, and 90 days after TIA: Age ≥60 years, initial Blood pressure ≥140/90 mm Hg, Clinical features of focal weakness or impaired speech without focal weakness, Duration 10 to 59 minutes or ≥60 minutes, and Diabetes
a
Cardiovascular causes of death, including stroke, are the greatest contributors to the 5-year disparity in life expectancy for African American men compared to white men and the 4-year racial disparity for women.49 However, the racial gap in life expectancy has recently been declining
a
History and careful neurologic examination to assess level of consciousness and focal findings are essential for diagnosing stroke, followed by neuroimaging to distinguish ischemic from hemorrhagic stroke
a
Stroke subtypes include: TIA; ischemic— cardioembolic, large artery atherosclerotic, lacunar, or cryptogenic; hemorrhagic—intracerebral, subarachnoid; and other—dural sinus venous thrombosis, carotid and vertebral artery dissection, or asymptomatic aneurysm
a
The Mini-Mental State Examination,
which takes 7 to 10 minutes to administer,
is the best studied, and at a score
cutpoint of 23 to 24, has a median
likelihood ratio (LR) of 6.3 for a positive
test and 0.19 for a negative test
a
Loss of smell occurs in sinus conditions,
head trauma, smoking, aging,
use of cocaine, and Parkinson disease
a
Inspect each disc carefully for bulging
and blurred margins (papilledema);
pallor (optic atrophy); and cup
enlargement (glaucoma
a
Look for prechiasmal, or anterior, defects seen in glaucoma, retinal emboli, optic neuritis (visual acuity poor); bitemporal hemianopsias from defects at the optic chiasm, usually from pituitary tumor; and homonymous hemianopsias or quadrantanopsias in postchiasmal lesions, usually in the occipital or parietal lobe, with associated findings of stroke (visual acuity normal).84
a
If the large pupil reacts poorly to light or anisocoria worsens in light, the large pupil has abnormal pupillary constriction, seen in CN III palsy. If ptosis and ophthalmoplegia are also present, consider intracranial aneurysm if the patient is awake, and transtentorial herniation if the patient is comatose.
a
If both pupils react to light and anisocoria worsens in darkness, the small pupil has abnormal pupillary dilation, seen in Horner syndrome and simple anisocoria
a
Monocular diplopia is seen in local problems with glasses or contact lenses, cataracts, astigmatism, or ptosis. Binocular diplopia occurs in CN III, IV, and VI neuropathy (40% of patients), and eye muscle disorders from myasthenia gravis, trauma, thyroid ophthalmopathy, and internuclear ophthalmoplegia.86
a
Nystagmus is seen in cerebellar disease, especially with gait ataxia and dysarthria (increases with retinal fixation), and vestibular disorders (decreases with retinal fixation); and in internuclear ophthalmoplegia
a
Ptosis is seen in 3rd nerve palsy (CN III),
Horner syndrome (ptosis, miosis,
forehead anhidrosis), or myasthenia
gravis.
a
Difficulty clenching the jaw or moving it to the opposite side suggests masseter and lateral pterygoid weakness, respectively. Jaw deviation during opening points to weakness on the deviating side
a
Look for unilateral weakness:
bilateral weakness in:
(neuro)
CN V pontine lesions
bilateral hemispheric disease
CNS patterns from stroke include ipsilateral
facial and body sensory loss
from contralateral cortical or thalamic
lesions; ipsilateral face, but contralateral
body sensory loss in brainstem
lesions.
a
Isolated sensory loss occurs in peripheral
nerve disorders, including lesions
of the trigeminal nerve (CN V).
a
Blinking is absent in both eyes in
Absent blinking and sensorineural hearing loss occur in
CN V lesions and on the side of weakness in lesions of CN VII
acoustic neuroma
Flattening of the nasolabial fold and
drooping of the lower eyelid suggest
facial weakness
A peripheral injury to CN VII, as seen in Bell palsy, affects both the upper and lower face; a central lesion affects mainly the lower face. Loss of taste, hyperacusis, and increased or decreased tearing also occur in Bell palsy.8
a
In unilateral facial paralysis, the
mouth droops on the paralyzed side
when the patient smiles or grimaces.
a
The whispered voice test is both sensitive
(>90%) and specific (>80%)
when assessing presence or absence
of hearing loss
a
Excess cerumen, otosclerosis, and otitis
media cause conductive hearing
loss; presbyacusis from aging is usually
from sensorineural hearing loss
a
Vertigo with hearing loss and nystagmus
typifies Ménière disease
a
Hoarseness occurs in vocal cord
paralysis; nasal voice in paralysis of
the palate
a
Difficulty swallowing suggests pharyngeal
or palatal weakness.
a
The palate fails to rise with a bilateral
lesion of CN X. In unilateral paralysis,
one side of the palate fails to rise and,
together with the uvula, is pulled
toward the normal side
a
Unilateral absence of this reflex suggests
a lesion of CN IX, and perhaps
CN X
a
Trapezius weakness with atrophy and fasciculations points to a peripheral nerve disorder. In trapezius muscle paralysis, the shoulder droops, and the scapula is displaced downward and laterally
a
A supine patient with bilateral weakness
of the SCM muscles has difficulty
raising the head off the pillow
a
Tongue atrophy and fasciculations
are present in amyotrophic
lateral sclerosis and past polio
a
