Infectious Flashcards
What CD4 count predisposes to toxoplasmosis brain lesions?
<100
Where is toxoplasmosis typically found in the brain?
The basal ganglia/thalamic region
What are Argyll Robertson pupils?
They are bilateral small pupils that reduce in size on a near object (i.e., they accommodate), but do not constrict when exposed to bright light (i.e., they do not react to light) - “light-near dissociation”. They are a highly specific sign of neurosyphilis
What bacterial disease can present with absence of DTRs and a positive Romberg sign?
Neurosyphilis
What is the most common etiology of cavernous sinus thrombosis?
Uncontrolled infection of the central facial skin, the orbit, or nasal sinuses that leads to septic thrombosis. Staph aureus is the most common causative agent
What is postinfectious cerebellitis?
Typically affects children between ages of 2 and 7 and usually follows a varicella or other viral infection. Children present with acute onset of limb and gait ataxia as well as dysarthria. Dx of exclusion
What is Miller Fisher syndrome?
Thought to be a variant of Guillain-Barré syndrome that leads to a triad of ataxia, areflexia, and ophthalmoplegia. The ataxia is due to loss of proprioception rather than cerebellar causes. Thought to be postinfectious and most patients recover fully
What is PANDAS?
Pediatric autoimmune neurologic disorders associated with streptococcal infection. The child develops exacerbation of tics, OCD or both following a group A beta-hemolytic strep infection
What is progressive multifocal leukoencphalopathy (PML) and what causes it?
Caused by the JC virus and leads to demyelination by infecting oligodendrocytes. Leads to dementia, focal cortical dysfunction, and cerebellar abnormalities. Mortality is ~50%
How does tuberculosis meningitis differ from acute pyogenic bacterial meningitis?
It has a predilection for affecting the basal meninges leading to cranial nerve palsies and more commonly causes hydrocephalus and brain infarcts. It also has a more subacute presentation with a prolonged prodrome of malaise and nonspecific constitutional symptoms. The CSF profile demonstrates a leukocytosis with lymphocytic predominance (as opposed to PMNs) and CSF glucose is often very low.
What are the neurologic complications associated with Lyme disease?
Aseptic meningitis and/or facial nerve palsy within weeks after infection. Later manifestations include leukoencphalopathy and painful polyradiculopathy
What are symptoms of HSV1 encephalitis?
Tends to infect the medial temporal lobes and orbitofrontal regions of the cortex leading to limbic dysfunction (e.g. complex partial seizures of mesial temoral lobe origin, olfactory hallucinations and memory disturbances including sometimes profound anterograde amnesia). The CSF profile often demonstrates and elevated RBC count and leukocytosis. Treated with prolonged IV course of acyclovir
What is the CSF profile of fungal meningitis?
Lymphocytic predominance, elevated protein and low glucose
What is vaculoar myelopathy?
A late complication of severe immunosuppression cause by HIV. It resembles B12 deficiency with loss of vibration and joint position sense (dorsal column), with sensory ataxia along with corticospinal tract dysfunction (spasticity and hyperreflexia) bilaterally. May also cause urinary and sexual dysfunction.
What are the autoantibodies in Guillain-Barré syndrome (GBS) directed against?
Gangliosides (e.g. anti-GM1 is most common, may also see anti-GD1a, antiGQ1b, etc)
How does Guillain-Barré syndrome present?
Areflexic motor paralysis with or without sensory disturbances, including neuropathic pain
