Hereditary neuropathy with liability to pressure palsies and amyotrophic lateral sclerosis.

A 56-year-old male with recurrent painless focal neuropathies and a family history of peripheral neuropathy of unknown etiology presented with progressively worsening of impaired sensations and weakness in his lower extremities. His initial electrodiagnostic evaluation was suggestive of severe sensory and motor peripheral polyneuropathy. The genetic testing was performed for familial causes of peripheral neuropathy as there was a family history of peripheral neuropathy of unknown etiology. The patient was found to have 1.5-Mb deletion in the PMP22 gene which was confirmatory of hereditary neuropathy with liability to pressure palsies (HNPP). He developed progressive upper and lower extremity weakness, bulbar dysfunction and widespread fasciculations during the course of his illness. He was subsequently diagnosed with amyotrophic lateral sclerosis (ALS). This is the second reported case of HNPP associated with ALS. We discuss significant clinical and electrodiagnostic findings of this interesting case.

Periodic lateralized epileptiform discharges: an initial electrographic pattern in reversible posterior leukoencephalopathy syndrome.

Reversible posterior leukoencephalopathy (RPLE) is a unique clinicoradiological entity characterized by diverse neurological symptoms with bilateral posterior cerebral white matter edema. It is frequently associated with seizures but rarely with status epilepticus. Periodic lateralized epileptiform discharges (PLEDs) as an initial electrographic pattern in a patient with RPLE have never been reported. We discuss a 47-year-old woman with a newly diagnosed non-small cell carcinoma of the lung on etoposide who was admitted with encephalopathy. Initial EEG demonstrated PLEDs. She later developed nonconvulsive status epilepticus. Magnetic resonance imaging (MRI) revealed bilateral subcortical edema predominantly of the temporo-occipital lobes. Discontinuation of etoposide resulted in full clinical, electrical recovery within 10 days and significant radiological improvement within 15 days. Our case indicates the importance of identifying and addressing any modifiable etiologic factors of RPLE. We emphasize identification of the unique initial electrographic pattern of PLEDs, which may be a predisposing factor to status epilepticus or an indication of structural damage.