·
Although episodes of vertigo associated with Meniere syndrome usually last from hours to a
day, deafness is constant after it develops. The
deafness is characterized initially by a compromised ability to hear
low-frequency sounds. Tumarkin otolithic crisis
is a sudden spell of falling to the ground associated with Meniere syndrome.
Meniere syndrome can be associated with nausea and vomiting.
·
Acanthocytes
are seen in abetalipoproteinaemia. Retinitis pigmentosa is seen in
abetalipoproteinaemia. Mental retardation is not
present but motor abnormalities and neurodegenerative are seen.
·
Episodes of
vertigo in middle-aged patients should prompt consideration of vertebrobasilar
insufficiency as a cause. The vertigo can represent transient
ischemic attacks, which are warning signs of possible vertebrobasilar
occlusion, a life-threatening condition.
·
Vestibular
neuritis is quite common, second only to BPPV as a cause of vertigo
in most dizziness clinics. It is frequently associated with an upper
respiratory tract infection and usually lasts from days to weeks. Hearing is uniformly preserved.
·
The severity of the diabetic
polyneuropathy correlated more closely with the degree of hyperglycemia (mean glycosylated
hemoglobin) than with the duration of diabetes. ( cf: in retinopathy, its duration.)
·
Malignant
hyperthermia is an autosomal dominant disorder caused by a defect on
chromosome 19q13, leading to a mutation of the ryanodine receptor (RyR) gene. Mutations of RyR cause accelerated
calcium release from the sarcoplasmic reticulum during general anesthesia with
compounds such as halothane, ether, and succinylcholine. This leads to a rapid
increase in metabolism, dramatic elevations of body temperature, acidosis,
muscle rigidity, myoglobinuria, and death. A careful family history may give
clues to the diagnosis and should prompt referral for a muscle biopsy and in
vitro caffeine-halothane contraction testing.
Patients with malignant hyperthermia can usually safely undergo
anesthesia with nitrous oxide, thiopental, and
nonpolarizing muscle relaxants. I.V. dantrolene is effective if
administered early in the disease course, but patients who develop the syndrome
still have a 7% mortality.
·
Hyperkalemic periodic
paralysis is caused by a defect of the sodium channel, precipitated by rest
following exercise, stress, potassium administration, and the ingesting of
certain foods. Hypokalemic periodic paralysis
is caused by a defect in the calcium channel and is precipitated by the
partaking of meals high in carbohydrates, rest following exercise, and
excitement. If the potassium level is found to be low during attacks,
secondary causes of hypokalemia (diuretics, hyperaldosteronism, laxatives,
etc.) or thyrotoxicosis (especially in patients of Asian descent) should be
sought. A serum potassium level that is elevated without apparent cause is
suggestive of hyperkalemic periodic paralysis.
·
Noncontrast CT reliably
distinguishes acute intracerebral hemorrhage from ischemia. This distinction is
critical because the management of hemorrhagic stroke is substantially
different from that of ischemic stroke.
·
ICH volume and
consciousness level are the two most powerful predictors of outcome in ICH.
Observations suggest that about one third of ICHs expand in the first 24 hours.
Some investigators have juxtaposed this fact with a need to lower blood
pressure in acute ICH. Because it has been shown to improve outcome, nimodipine, a calcium channel blocker, is
begun on the first day and continued for 21
days.
·
MTBI (mild traumatic
brain injury) is defined as any traumatic brain injury/concussion
with loss of consciousness of 0 to 30 minutes, a GCS score of 13 to 15 on
admission, posttraumatic amnesia or confusion lasting less than 24 hours, and
no evidence of contusion or hematoma on CT.
·
Corticosteroids
should not be used for neuroprotection or control of ICP in patients with
severe TBI.
·
The risk of epilepsy in
patients with closed-head injury is relatively small: 2% to 5% in all
patients and about 10% to 20% in patients with severe closed-head
injury. A higher incidence of seizures has been seen in patients with depressed
skull fractures (15%), hematomas (31%), and penetrating brain wounds
(50%).
Because
most patients who develop posttraumatic epilepsy in
the first week after injury will have recurrent seizures for some
time, anticonvulsant therapy is indicated in documented cases. Controlled,
randomized studies have shown that the use of phenytoin,
phenobarbital, carbamazepine, and valproate do not prevent the
development of posttraumatic epilepsy beyond the first week after injury.
·
As with other metastatic
tumors, breast cancer tends to produce multiple lesions that are most commonly
located at the junction of the white matter and
gray matter.
Of interest, women with breast cancer are known to have an increased
incidence of meningiomas. Prognosis of meningiomas is in general
excellent; surgical excision tends to be curative.
·
The peripheral
nervous system is affected by two different sets of antibodies. Both
peripheral neuropathies are predominantly sensory. In patients with lymphoma and Waldenström disease,
myelin-associated glycoprotein antibodies (anti-MAG)
are produced. Anti-Hu antibodies are found in patients with
peripheral neuropathy and encephalomyelitis associated with small cell
carcinoma of the lung.
Because of the
clear relationship between ovarian cancer and paraneoplastic
cerebellar degeneration due to anti
Yo antibodies.
·
The persistent
vegetative state is characterized by the return
of sleep-wake cycles and of various reflex activities, but wakefulness is
without awareness. Recent studies have indicated that the minimally
conscious state, which is characterized by inconsistent but clearly discernible
behavior of consciousness, can be distinguished from coma and a vegetative
state by the presence of behavioral conditions not found in either of those two
conditions; this distinction is important because outcome appears to be
different in minimally conscious patients. Brain
death is defined as the loss of all cerebral
activity, including activity of the cerebral cortex and brain stem, for at
least 6 hours if confirmed by electroencephalographic evidence of
electrocerebral inactivity or for 24 hours without a confirmatory
electroencephalogram.
·
Thiamine
replacement therapy rarely leads to improvement in Korsakoff’s Psychosis.
·
Chronic daily
headache (CDH) includes four different headache types: transformed migraine, chronic tension-type headache,
hemicrania continua, and new drug persistent headache.
·
Friedreich ataxia
is the most common recessively inherited ataxia. Patients often present before
the age of 25 years with ataxia. Other symptoms can include dysarthria, vision
problems, weakness, and dysphagia. Physical examination reveals loss of deep
tendon reflexes, poor proprioception, weakness, and extensor plantar response.
Phenotypic variation is not uncommon, and some patients have preserved or brisk
deep tendon reflexes. Between 30% and 50% of
patients develop symptomatic heart disease, including hypertrophic cardiomyopathy.
·
The longer-acting agent clonazepam may be a better choice for depression
in AD. Buspirone is another
alternative for the treatment of anxiety in AD patients. Treatment of agitation
generally requires antipsychotics. Quetiapine
has the significant advantage of being much less likely to induce
extrapyramidal signs than both newer and older agents.
·
Patients with DLB
often experience marked fluctuations in their alertness and level of arousal
from one day to the next. They often sleep excessively. In RBD, patients engage
in dream enactment, thrashing about in bed or talking in their sleep. RBD can often precede the dementia and the
movement disorder by years and is highly specific
for DLB.
·
Two medications that often cause cognitive
dysfunction: amitriptyline (a
tricyclic antidepressant with anticholinergic activity) and lorazepam (a benzodiazepine). These medications
should be changed or discontinued before considering the diagnosis of a primary
dementia syndrome.
·
Pseudoseizures;
currently, the preferred term for such seizures is nonepileptic
seizures. Use of this term tends to help the patients understand
their problem and facilitates referral for behavioral therapy. An important
clue to the diagnosis of nonepileptic seizures is that they are periodic
events that tend not to be stereotyped. Both patients and observers
report varied behaviors with each event. Another clue is the prolonged
duration. Nonepileptic seizures may last 30 minutes to several hours—longer
than typical seizures. Patients with both nonepileptic seizures and epilepsy
pose a challenging problem; this combination is occasionally found in patients
undergoing assessment in epilepsy monitoring units.
·
Narcolepsy
is a disorder of unknown etiology. A strong association exists between narcolepsy
and the presence of the DR-15 subtype of DR2
and the DQB1*0602 subtype of DQw1
haplotypes. The most exciting recent development in our understanding of
narcolepsy is the documentation of an abnormality in the hypocretin neurons in
the lateral hypothalamus. Human narcolepsy-cataplexy can be considered a hypocretin (orexin) deficiency syndrome.
·
Partial arousal
disorders include confusional arousals, sleepwalking
(somnambulism), and sleep terrors (pavor nocturnus). These conditions are a
subset of the parasomnias: disorders that occur during the sleep-wake
transitions and during partial arousals. Parasomnias
are characterized by abnormal movements or behaviors that intrude into sleep without disturbing sleep architecture. An overnight
sleep study with simultaneous video recording can confirm unusual movements or
behavior during nighttime sleep in patients with parasomnias. Most partial
arousal disorders are benign.
·
Pain is a subjective experience, and its
expression is unique to each patient. Often there is little objective evidence
with which to assess the source or intensity of pain. Thus, one of the most
important aspects of the patient-physician relationship regarding the treatment
of chronic pain is trust: the
physician is obligated to rely on the patient’s self-reports of pain; to do
otherwise may be unethical. Pain is a complex process that involves biologic
and psychosocial factors.
·
In patient with a known seizure disorder, a combination of acetaminophen and codeine is a safe choice for
short-term treatment of pain. Tramadol, a nonnarcotic analgesic
that binds to mu opiate receptors in the CNS and causes inhibition of ascending
pain pathways, is contraindicated in this patient because it
tends to make seizures worse. Similarly, tricyclic antidepressants
and the opioid analgesic meperidine can induce seizures
and thus would not be the best initial choice.
·
The combination of parkinsonism, autonomic
insufficiency, and ataxia is strongly suggestive of multiple
systems atrophy.
·
HSV-2 is the primary
cause of benign recurrent lymphocytic meningitis. Unlike viral
meningitides that have a seasonal association, HSV-2 meningitis occurs at any
time of year. The typical symptoms and signs are headache, fever, stiff neck,
and a marked lymphocytic pleocytosis in the CSF.
·
Unlike most viral encephalitides, HSV-1 encephalitis is focal. HSV replication in
the medial temporal lobe and orbital surface of the
frontal lobe, with accompanying inflammation, produces the
characteristic clinical picture. Fever, headache, lethargy, irritability, and
confusion are typical symptoms. Seizures (major motor, complex partial, focal,
and even absence attacks) affect approximately 40% of patients. If the dominant
temporal lobe is involved, aphasia and focal motor or sensory deficits develop.
The CSF is usually abnormal in HSV encephalitis.
Although RBCs are unusual in other viral
encephalitides, in HSV encephalitis they are often present in the CSF, which
may also be xanthochromic; this presumably reflects the hemorrhagic
nature of brain lesions. Instead of attributing the presence of RBCs in CSF to
a so-called traumatic tap, the astute clinician may
use this finding to support the presumptive diagnosis of HSV encephalitis.
·
Radiologic
findings can be similar in HAM and multiple sclerosis. Both diseases
can cause elevated IgG and oligoclonal bands in the CSF. Although HAM is
reported mainly in Japan, the Caribbean region, and Central America, it does
occur in the southeastern United States. HTLV-I can also cause a T cell
lymphoma/leukemia, and although it is rare to have the neurologic and
hematopoietic complications occur at the same time, this patient’s skin biopsy
is characteristic of a cutaneous lymphoma. Serology testing should be done to
confirm HTLV-I infection.
Remember that in MS, the total
protein concentration Iis usually normal; however, Ig levels are high relative
to other protein components. The predominant Ig is IgG, although IgM and IgA are also
increased. The IgG index is used to measure the increase in IgG levels relative
to other proteins. Also CSF pressure is normal, protein is normal, and cell
count is normal.
·
Variant CJD
is believed to be the accidental transmission to humans of the agent of bovine
spongiform encephalopathy (mad cow disease). It differs
from CJD in that it occurs in younger patients. Patients present
with psychiatric disturbances; dementia develops much later. Patients with CJD lack characteristic EEG findings and have
a longer survival time. This patient had classic findings of CJD:
visual changes, dementia, ataxia, myoclonic jerks, a characteristic EEG study,
and rapid progression to death.
·
On MRI, the lack
of contrast enhancement is typical for PML, as distinct from
toxoplasmosis, lymphoma, or astrocytoma. Bizarre cells are seen on biopsy but do
not indicate the presence of a malignancy. The intranuclear
inclusions in the oligodendrocytes are typical for PML. There are no
proven therapies of benefit in managing PML, although it is believed that
partial reversal of the immunodeficient state may be responsible for transient
improvement.
·
Nonsteroidal
anti-inflammatory drugs can cause a meningoencephalitis, especially in patients
with underlying collagen vascular diseases.
·
·
Cerebellar problems can present as three diseases:
Ataxia – telangiectasia
- Telangiectasia all over skin
- lady with spider veins
- Have IgA deficiencies
- diarrhea, respiratory illness
Fredriechs Ataxia
- Retinitis pigmentosa (pigments on the retina)
- Scoliosis (5-10%)
Adrenoleukodystropy
- adrenal gland is knocked out
- electrolyte problems
- Long chain fatty acids accumulation in the mitochondria (transferred by carnitine)
- Involvement of Cortex early on
- spasticity
- babinsky
·
Gerstmann–Sträussler–Scheinker syndrome (GSS) is a
very rare, usually familial, fatal neurodegenerative disease that affects
patients from 20 to 60 years in age. This extremely rare disease is classified
as a transmissible spongiform encephalopathy.
GSS is one of a
small number of diseases which are caused by prions, a class of pathogenic
proteins highly resistant to proteases.
Symptoms start
with slowly developing dysarthria (difficulty speaking) and cerebellar ataxia
(unsteadiness) and then the progressive dementia becomes more evident.
There is no cure or treatment for GSS and patients rarely
survive longer than five years.
·
Neuroblastoma is the most common extracranial
solid tumor in infancy. It is an embryonal malignancy of the sympathetic
nervous system arising from neuroblasts (pluripotent sympathetic cells).
undifferentiated neuroblastomas histologically present as small, round, blue
cell tumors with dense nests of cells in a fibrovascular matrix and
Homer-Wright pseudorosettes. These pseudorosettes, which are observed in 15-50%
of tumor samples, can be described as neuroblasts surrounding eosinophilic
neuritic processesA neuritic process, also called neuropil, is a pathognomonic
feature of neuroblastoma cells.
Shimada histopathologic classification system
Important features
of the classification include (1) the degree of neuroblast differentiation, (2)
the presence or absence of Schwannian stromal development (stroma-rich,
stroma-poor), (3) the index of cellular proliferation (known as
mitosis-karyorrhexis index [MKI]), (4) nodular pattern, and (5) age.
Joshi histopathologic classification system
This system
classifies tumors based on the presence of calcification and mitotic rate, as
follows: (1) good prognosis (ie, low mitotic rate and calcification), (2)
intermediate prognosis (ie, low mitotic rate or calcification), and (3) poor prognosis
(ie, high mitotic rate and no calcification).
·
Mutations affecting nonmuscle myosin heavy-chain
type II-A results in MYH9-related hereditary macrothrombocytopenia syndromes,
including 4 autosomal dominant
platelet disorders (ie, Fechtner syndrome, Epstein syndrome, May-Hegglin
syndrome, and Sebastian syndromes).
Epstein's syndrome
is defined as a subtype of Alport's syndrome, and is distinguished from the
other subtypes by accompanying macrothrombocytopenia.
Epstein's syndrome
is a rare inherited disorder that appears principally as nephritis and deafness
with thrombocytopathic thrombocytopenia producing a bleeding tendency. An
association between hereditary nephritis, deafness, and megathrombocytopenia is
reported as part of 2 distinct syndromes.
Fechtner syndrome
consists of nephritis, sensorineural hearing loss, cataracts,
macrothrombocytopenia, and characteristic polymorphonuclear inclusion bodies.
Epstein syndrome is similar to Fechtner syndrome but without neutrophilic
inclusions. Transmission appears to be autosomal dominant in both syndromes.
·
Anton-Babinski syndrome, is a rare symptom of
brain damage occurring in the occipital lobe. People who suffer from it are
"cortically blind," but affirm, often quite adamantly and in the face
of clear evidence of their blindness, that they are capable of seeing. Failure
to see is dismissed by the sufferer through confabulation.
·
The presence of anti-Jo-1 antibody in patient of PM/DM is
a marker for interstitial lung disease.
·
Guillain-Mollaret triangle: This is not an
anatomical triangle but a triangular circuit connecting the dentate nucleus of
the cerebellum of one side with the red nucleus and the inferior olive on the
other side, via the superior cerebellar peduncle, the central tegmental tract,
and the inferior cerebellar peduncle.
·
In TBME, CN palsies may be either unilateral or
bilateral and most commonly occur in CN VI (abducens, usually bilateral).
Palsies may also develop in CN III (oculomotor) > CN IV (trochlear) > CN
II (optic).
·
Viral encephalitis is caused by a number of
arboviruses belonging to the families Flaviviridae,
Togaviridae, Bunyaviridae, and Reoviridae; other zoonotic viruses
can also cause viral encephalitis. Almost all viruses that cause encephalitis
are transmitted by either mosquitoes or ticks. Of those transmitted by mosquitoes, the majority have a bird vertebrate host. The exceptions are the encephalitides caused by
Bunyaviridae, which include La Crosse encephaliti (rodent host)s; California
encephalitis; some viruses of the Togaviridae family, including Venezuelan
equine encephalitis; and some cases of Western equine encephalitis.
St. Louis encephalitis, West Nile encephalitis, and Murray Valley encephalitis
are all transmitted by mosquitoes that have birds as their vertebrate host.
·
With an incidence of 180 per 100,000 people,
MTBI is more common than any other neurologic diagnosis except migraine. MTBI is defined as any traumatic brain
injury/concussion with loss of consciousness of
0 to 30 minutes, a GCS score of 13 to 15 on admission, posttraumatic amnesia or
confusion lasting less than 24 hours, and no evidence of contusion or hematoma
on CT. Although the emergency department evaluation and management
of MTBI is controversial, the principal concern is with identifying evolving
surgical lesions such as hematomas and contusions. In addition to history and
examination, CT has become the mainstay of evaluation. Prolonged or
deteriorating mental status or the presence of neurologic signs or other risk
factors are still indications for CT scanning, observation, or both after MTBI.
MRI promises to be very useful in the long-term management of moderate and
severe TBI, as well as in the documentation of brain pathology in patients with
milder injury. However, it is often impractical and not cost-effective in the
acute setting. This patient has MTBI, and observation for a few hours and
possibly a CT scan to rule out contusions are appropriate. He does not have
severe enough trauma to warrant admission or invasive monitoring of his ICP.
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