Acquired Metabolic Disorders

Question 1

Serum osmalality formula

Answer 1

OSM=2 x Na + glucose/18 + BUN/3

Question 2

When the CBF falls below 60-70mmHg, this form of additional compensation allows normal energy metabolism to continue.

Answer 2

Increased oxygen extraction

Question 3

“No-reflow” phenomenon

Answer 3

Swelling of the endothelium and blockage of circulation to the ischemic cerebral tissues causing irreversibility of ischemic lesions

Question 4

Most common early change in severe anoxic-ischemic injury

Answer 4

Loss of distinction between the cerebral gray and white matter

Question 5

Clinical signs at 1 day after cardiac arrest that predict a poor neurologic outcome

Answer 5

1. Absent corneal response
2. Absent pupillary reactivity
3. Absence of withdrawal to pain
4. Absence of any motor response

@72H, absence of motor response is an addtl poor prog sign

Question 6

Drug of choice for polymyoclonus

Answer 6

Clonazepam 8-12mg daily

Question 7

At what level of carboxyhemoglobin do coma, decerebrate or decorticate posturing, seizures and slowing of EEG rhythms seen?

Answer 7

At 50-60% of total hemoglobin

Question 8

Early symptoms of CO poisoning

Answer 8

Headache, nausea, dyspnea, confusion, dizziness and clumsiness

Question 9

Delayed neurologic deterioration from CO poisoning occurs at least how long after exposure?

Answer 9

1-3weeks

Usu extrapyramidal features

Question 10

Characteristic imaging finding in CO poisoning

Or in other forms of anoxia

Answer 10

Discrete areas of decreased attenuation in the B globus pallidus, sometimes inner putamen

Question 11

2 Common features among patients who developed delayed extrapyramidal symptoms

Answer 11

1. Prolonged period of pure anoxia

2. Basal ganglia lesions on CT

Question 12

When to intiate hyperbaric oxygen for CO poisoning on top of inspired oxygen?

Answer 12

Carboxyhemoglobin >40%
OR
(+) coma or seizures

Question 13

Main features of Chronic mountain sickness or Monge disease

Answer 13

Pulmonary hypertension
Cor pulmonale
Secondary polycythemia

Question 14

Most effective preventive measure to counteract mountain sickness

Answer 14

Acclimatization by 2-4-day stay at intermediate altitudes

Question 15

Glucose level which manifests as a confusional state and seizures? Which causes coma and irreparable brain injury?

Answer 15

30mg/dL

10mg/dL - coma and irreparable brain injury

Question 16

Glucose reserve of the brain

How long is this able to sustain cerebral activity?

Answer 16

1-2g (30 mmol/100g tissue)
Used at a rate of 60-80 mg/min
Sustains activity for 30min or less

Question 17

Combined use of corticosteroids and this AED, esp in elderly patients with brain tumors, can precipit Hyperosmolar nonketotic hyperglycemia

Answer 17

Phenytoin - as it inhibits insulin release

Question 18

Usual concentrations of NH3 in arterial blood seen in hepatic/ portal-systemic Encephalopathy?

Answer 18

In excess of 200 mg/dL

Question 19

Neuropathologic changes in hepatic coma

Answer 19

Diffuse inc in size and number of protoplasmic astrocytes in the deep layers of correx, lenticular nuclei, thalamo, Substantia nigra, cerebellar cortex red, dentate and pontine nuclei

Alzheimer Type II astrocytes

Question 20

Pathologic findings in Reye Syndrome

Answer 20

Cerebral edema often with Cerebellar herniation

Infiltration of hepatocytes with fine droplets of fat

Question 21

Oral administration of this drug in hepatic Encephalopathy suppresses the urease-producing organisms in the bowel but may cause renal damage and ototoxicity. Hence it was replaced with Rifaximin.

Answer 21

Neomycin

Question 22

Neuropathologic changes in Dialysis Encephalopathy

Answer 22

Mild degree of microcavitation of the superficial layers of the cerebral cortex (more severe in the L frontotemporal operculum than the rest of the cortex)

Question 23

Fluid restriction in SIADH

Answer 23

Na <120meq/L - 500mL/24hrs

Na <130meq/L - 1000mL/24hrs

Question 24

To prevent central pontine myelinolysis from overly rapid Na correction, the rate should be:

Answer 24

Nk more than 10 mmol/L in the first 24hrs

Question 25

Fundamental abnormality in osmotic demyelination

Answer 25

Destruction of myelinated sheaths throughout the lesion, with relative sparing of axons and intactness of nerve cells of pontine nuclei Oligodendrocytes depleted Signs of inflam absent

Question 26

Pathology of acquired hepatocerebral degeneration

Answer 26

Irregular line of necrosis or gliosis throughout both hemispheres and the lenticular nuclei may be shrunken and discolored. Resemble hypoxic ones but spares hippocampus, globus pallidus, and deep folia of cerebellar cortex. Widespread hyperplasia of protoplasmic astrocytes Necrotic zones where myelinated fibers and nerve are destroyed Opalski cells - nerve cells swollen and chromatolyzed like in Wilson

Question 27

Sprue is associated with which HLA genotypes in 90% of cases?

Answer 27

HLA DQ2 | HLA DQ8

Question 28

Dose of prednisone at which 10-15% of patients show symptoms o corticosteroid psychoses

Answer 28

60-100 mg/day

Question 29

Antibodies against gluten seen among patients with and without clinical enteropathy of celiac disease that correspond to the presence of neurologic manifestations.

Answer 29

antigliadin antibodies

Question 30

Two forms of endemic cretinism and their manifestations

Answer 30

Neurologic cretinism - deaf-mutism, dysarthria, proximal limb and truncal rigid-spastic motor disorder mainly LE - mental deficiency - lack of iodine 2nd-3rd trim so need to provide iodine inbefore and during 1st trim Myxedematous - short stature, microcephaly, coarse facial features, retarded psychomotor devt - lack of thyroid hormone in the late second and third trimesters