Snapshot A 32-year-old man presents to the emergency department with worsening lower extremity weakness. The patient was in his usual state of health until approximately one week prior to presentation, where he developed increased difficulty climbing the stairs. Now he is unable to stand. A few weeks ago he developed bloody diarrhea, which he attributes to drinking unpasteurized milk. On physcal examination, he has bilateral lower extremity 1/5 strength with absent patellar reflexes. (Guillain-Barre syndrome) Guillain-Barré Syndrome Introduction acute inflammatory demyelinating polyradiculopathy (AIDP) most common presentation decreased axonal conduction speed inflammatory demyelination of peripheral nerves autoimmune attack of peripheral Schwann cells due to molecular mimicry previous Campylobacter jejuni and Mycoplasma pneumoniae may have an association with Zika virus infection Presentation symptoms symmetric weakness usually begins in distal limbs and moves proximally can begin proximally or a combination of proximally and distally physical exam decreased or absent deep tendon reflexes cranial nerve involvement common resulting in facial paralysis autonomic dysfunction resulting in cardiac irregularities and fluctuations in blood pressure Evaluation LP albuminocytologic dissociation ↑ CSF protein with normal cell count Treatment almost all patients survive and achieve complete recovery in several weeks respiratory support is critical until recovery pulmonary function testing plasmapheresis or IV immunoglobulin equal efficacy; no additive benefit Prognosis, prevention, and complications prognosis low mortality complications respiratory failure Progressive Multifocal Leukoencephalopathy (PML) Introduction widespread CNS demyelination due to destruction of oligodendrocytes associations latent JC virus reactivation ↑ risk with natalizumab ↑ risk with rituximab seen in the immunosuppressed HIV infection < 200 per mm3 organ transplant patients Presentation subacute neurological deficits e.g., hemiparesis, monoparesis, ataxia, altered mental status Evaluation clinical diagnosis with MRI imaging MRI symmetric or asymmetric lesions in multifocal areas PCR of CSF for JC virus brain biopsy Treatment patients with HIV antiretroviral therapy natalizumab-associated stop agent initiate plasma exchange Prognosis, prevention, and complications prognosis HAART therapy improves survival in patients with HIV prevention improving CD4+ count in patients with HIV complications death Acute Disseminated (Postinfectious) Encephalomyelitis Introduction autoimmune inflammatory demyelination of the CNS secondary to infection or vaccination via infection e.g., chickenpox and measles via vaccinations e.g., rabies and smallpox Presentation symptoms acute and rapidly progressive development multifocal neurological deficits altered mental status motor deficits cranial nerve neuropathy ataxia sensory deficit Evaluation clinical diagnosis Treatment high-dose corticosteroids IVIG or plasma exchange if poor response acyclovir Prognosis, prevention, and complications prevention no small pox vaccine before 12 months of age complications neurologic impairment Metachromic Leukodystrophy Introduction autosomal recessive lysosomal storage disease due to deficient arylsulfatase A inability to degrade sulfatides → sulfatide build up → myelin breakdown Presentation symptoms diverse neurological impairment depending on subtype e.g., motor skill regression in late infantile subtype Evaluation arylsulfatase enzyme activity in leukocytes decreased biopsy neural tissue metachromatic lipid deposits Treatment no curative treatment Charcot-Marie-Tooth Disease Introduction also known as hereditary motor and sensory neuropathy (HMSN) group of disorders negatively affecting peripheral nerves and/or myelin genetically distinct disorders Presentation symptoms peroneal nerve neuropathy lower leg atrophy "inverted bottle" appearance diminished or absent reflexes decrease vibration and proprioception sense pes cavus Treatment supportive Central Pontine Myelinolysis (CPM) Introduction pontine demylination loss of corticospinal and corticobulbar tracts due to rapid correction of hyponatremia can result in "locked-in syndrome" Presentation symptoms pseudobulbar palsy with spastic quadriparesis locked-in like presentation can move eyes and blink may also include cognitive function changes Prognosis often fatal