MetabEnceph Flashcards
Definition of a metabolic encephalopathy
subacute onset of a confusional state marked by fluctuating alterations of consciousness that progressively worsens if untreated
Pathophysiology of metabolic encephalopathy
diverese mechanisms lead to diffuse involvement of all brain structures
Signs and symptoms
- Altered mental status
- Seizures
- Altered respiration
- Altered pupil light reactivity- usually symmetric and sluggishly reactive, asymmetric or nonreactive pupils
Altered ocular motility- may be roving, dysconjugate, absent
Altered motor activity- diffuse alteration of strength, tone and reflexes. Tremor, asterixis (flapping of hands), multifocal myoclonus (rapid jerking of a limb)
Non-chemical or chemical more commonly lead to permanent brain injury
non- chemical: trauma, infxn, vascular, seizures
vitamins that lead to metabolic encephalopathy
B1
Niacin
B12
Wernicke Korsakoff syndrome often seen in what population
Alcoholics
Weinicke’s triad
1) Opthalmoparesis
2) Gait Ataxia
3) Confused State
What is the Korsakoff part of Weirnicke Korsakoff?
Korsakoff syndrome is generally defined by amnesia
Inappropriate treatment or repeated episodes leads to petechial hemorhage and atrophy to which brain areas
- Dorsomedial Thalamus atrophy and hemorrhage
- Mamillary body atrophy and hemorrhage
- Periaqueductal gray atrophy and hemorrhage
Tx of Wiernickes
Thiamine (IV) and then glucose
REMEMBER THIAMINE BEFORE GLUCOSE
Wiernicke Korsakoff is a deficiency of what?
B1
What are some other B1 deficiency syndromes
Wet Beriberi- high output CV failure
Dry Beriberi- polyneuropathy
Niacin deficiency causes
dementia and polyneuropathy…..rare
B6 deficiency
polyneuropathy in adults and seizures in kids
Vit B12 deficiency causes
pernicious anemia, fish tapeworm, gastric cancer, vegetarian diet, N20 abuse
Neurologic signs and symptoms of B12 deficiency
decreased vibration or position sense distal paresthesis weakness spastic gait visual impairment confusion, dementia, depression
Pathology of B12
demyelination of the dorsal columns, corticospinal tract, cerebral white matter, optic and peripheral nerves
Lab for B12
look or macrocytic anemia
Treat B12 deficiency how
cyanocabalamin weekly, treat underlying etiology
In B12 deficiency levels of what rise and are useful as tests to confirm thediagnosis
homocysteine and methylmalonic acid
In folate deficiency homocysteine will be normal but methylmalonic acid will be low
methylmalonic acid low
Vitamin B complex deficiencies cause
optic nerve disease:
- decreased visual acuity and central scotoma (blind spots). SOmetimes the central scotoma merges with physiological blind spot to causecentrocecal scotoma. More common when assoc with alc abuse
Hypoglycemia and Hyperglycemia can both cause encephalopathies
ok
Hypoglycemic encephalopathy shows what
confusion, seizures, dilated pupils, brisk reflexes, extensor plantar responses
Hyperglycemic encephalopathy
small pupils, no seizures, non-brisk reflexes,
Diabetic sensory neuropathy is often symmetrical
true
sensory neuropathy seen in upper or lower limbs
lower,,,,disturbs night sleep
Autonomic neuropathy in diabetics results in
atonic bladder
Hypoxic encephalopathy affects what parts of the brain
hippocampus, areas between vascular territories of major arteries, deep folia of cerebellum
Clinical features of hypoxic encephalopathy
coma, seizures, myoclnus,
Cerebral hypoxia most commony caused by
cardiac arrest
CO poisoning will appear as
Cherry red skin with cyanotic hue
tx of CO poisoning
hyperbaric O2
“awake but unaware”
status of ppl recovering from hypoxia
Hepatic encephalopathy
confusion, seizures, slow EEG with triphasic waves, asterixis, myoclonus, BRISK REFLEXES
Electrolytes that may cause encephalopathy
low sodium, calcium, magnesium or phosphate
Hyponatremia must be corrected….
SLOWLY- 8mEq per 24 hours otherwise you can get central pontine myelinolysis resulting in severe brainstem injury with impaired cognition or coma
