Diff Diagnosis List #2

Diff Diagnosis List #2

VI - Diff dx of Dementia
VII - Diff dx of ataxia and ophthalmoplegia
VIII - Diff dx of altered mental status, fever, headache
 IX - Diff dx of gradual onset hemiparesis
X - Workup of Multiple Sclerosis
XI - Brain death criteria
 
Diff dx of dementia

Vascular – Strokes, diffuse ischemic injuries
Infectious – Syphilis, chronic meningitis (TB, fungal), HIV dementia, PML, CJD
Trauma – SDH, dementia pugilistica
Autoimmune – CNS vasculitis, MS
Metabolic/toxic – hypothyroidism, vitamin B12, hepatic, renal failure, hypercalcemia, Korsakoff syndrome, heavy metal intoxication (lead, arsenic, bismuth), prolonged hypoglycemia, hypoxia
Idiopathic – Alzheimer’s disease, Parkinson’s dementia, dementia with Lewy bodies, PSP, MSA, ALS-Parkinson dementia of Guam, frontotemporal dementias, Wilson’s disease, primary progressive aphasia
Neoplastic – brain tumor, CNS lymphoma, paraneoplastic limbic encephalitis, postradiation effects
Miscellaneous – psuedodementia secondary to depression, complex partial seizures, NPH

Workup
Labs – CBC, BMP, LFT, vitamin B12, VDRL, TSH, ESR, HIV (if applicable), toxicology screen (if applicable)
Imaging – MRI brain
Lumbar puncture – therapeutic large volume tap, 14-3-3 protein assay (if applicable)
Depression screening
Head trauma screening

Diff dx of subacute presentation of ataxia and ophthalmoplegia

Miller Fisher variant of GBS
Wernicke’s encephalopathy
Toxins – botulism (ileus + fixed pupils), marine toxins, tick paralysis
Posterior circulation stroke
Myasthenia gravis
Hypothyroidism (peripheral neuropathy + cerebellar degeneration)
Paraneoplastic cerebellar degeneration

Workup:
Labs – CBC, BMP, LFT, TSH, Lyme titer (if applicable)
Imaging – MRI/MRA
Tx – thiamine + glucose
Lumbar puncture
EMG (if Miller Fisher, myasthenia gravis suspected)






Diff dx of altered mental status, fever, meningismus, headache

Vascular – SAH, ICH (BG, thalamus, cerebellar if HTN), SDH, epidural hematoma, bilateral thalamic CVA
Infectious – bacterial meningitis, tuberculous meningitis, viral encephalitis
Metabolic-toxic – HTN encephalopathy (if HTN present), DKA induced coma, hepatic, renal encephalopathy, hypothyroid (asterixis +)
Tumor – hemorrhage into tumor
Autoimmune – CNS vasculitis

Workup:
Labs: CBC, BMP, LFT, TSH, ESR
Imaging: CT or MRI brain
Lumbar puncture

Diff dx of gradual onset hemiparesis

Neoplastic – 1 neoplasm including astrocytoma, oligodendroglioma, 1 CNS lymphoma), metastasis
Infectious – Abscess (bacterial, parasitic such as echinococcus, toxoplasmosis, fungal such as aspergilloma, mucoymycosis)
Vascular – CVA, ICH, complicated migraine, hemorrhage from AVM or aneurysm
Traumatic – SDH, epidural hematoma, contusion
Autoimmune – CNS vasculitis, MS
Metabolic – Hypoglycemia
Psychiatric – Conversion disorder

Workup:
Labs: CBC, BMP, LFT, ESR
Imaging: CT or MRI brain with contrast
Lumbar puncture

Immunocompromised:
Includes HIV, CD4 titers, CXR, blood cultures

Common organisms in brain abscesses:

1. Bacterial – strep, staph aureus, pseudomonas, enterobacteria, anaerobes
2. Immunocompromised – Cryptococcus, toxoplasmosis

Workup for MS

Basic Labs – CBC, BMP, LFT, TSH
MS masqueraders – ESR, ANA, ACE, CXR, vitamin B12, VDRL, Lyme titer, if indicated HIV, HTLV-1
Imaging – MRI brain with contrast, if MRI brain suspicious or exam demonstrates myelopathy, MRI C, T-spine with contrast
Lumbar puncture – IgG synthesis index, oligoclonal bands
Evoked potentials – VEP (1st choice, esp with optic neuritis presentation), BAER, SSEP

Brain death criteria

Prerequisites to determine brain death
Cause known and irreversible
No confounding medical condition
NL metabolic (electrolytes, acid base status, endocrine)
No drugs or poison
T > 32 C

Exam
Coma
No motor response
Corneal reflexes absent
Caloric testing negative aftger 1 min after irrigation
Gag reflex absent
No response to suction
No sucking/rooting reflex
No respiratory drive on apnea test

Apnea test
T > 36.5, BP > 90, + fluid balance
Preoxygenate with 100% O2 for 10 mins
Start pulse ox/D/C ventilator
100% O2 6L via cannula
After 8 mins obtain ABG
If desaturation or hypotension occurs, draw ABG
+ if no respiratory drive with PCO2 > 60 mm Hg or > 20 mm Hg above baseline

Confirmatory tests
Angiogram – no filling
EEG – 8 electrodes, impedance < 10 KU, 2 uV sensitivity, 10 cm between electrodes, 30 minute recording, NONREACTIVE rhythm
TCD – lack of diastolic flow
SPECT: hollow skull 30, 60 mins, 2 hrs after injection
SSEP: absent responses