Postherpetic Anti-N-methyl-D-aspartate Receptor Encephalitis after Hemispherotomy in a Patient with Intractable Startle Epilepsy.

Herpes simplex encephalitis (HSE) has been increasingly reported after neurosurgical procedures, mostly after tumor resections in patients with a prior history of HSE. Early detection and appropriate treatment are essential to prevent high mortality of the disease; however, there are diagnostic difficulties due to nonspecific prodromal symptoms. In addition, anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis has been reported after HSE as an immunological relapse. Here, we report a case of postherpetic anti-NMDAR encephalitis following right hemispherotomy for intractable startle-induced seizures, to emphasize the importance of early diagnosis and appropriate treatment. To our knowledge, this is the first reported case of anti-NMDAR encephalitis after postoperative HSE, and the third reported case of hemispherotomy as a curative treatment for startle epilepsy.

Recessive PIEZO2 stop mutation causes distal arthrogryposis with distal muscle weakness, scoliosis and proprioception defects.

The genetic work-up of arthrogryposis is challenging due to the diverse clinical and molecular etiologies. We report a-183/12-year-old boy, from a 2nd degree consanguineous family, who presented at 36/12 years with hypotonia, distal laxity, contractures, feeding difficulties at birth. He required surgery for progressive scoliosis at 16 years of age, and walked independently since then with an unstable gait and coordination defects. His latest examination at 18 years of age revealed a proprioceptive defect and loss-of-joint position sense in the upper limbs. Somatosensory evoked potentials supported bilateral involvement of dorsal column-medial lemniscal sensory pathways and nerve conduction studies revealed a mild axonal neuropathy. Muscle biopsy showed myopathic changes with neonatal myosin expression. Mendeliome sequencing led to the discovery of a recessive stop mutation in piezo-type mechanosensitive ion channel component 2 (PIEZO2, NM_022068, c.1384C>T, p.R462*). PIEZO2 is a nonselective cation channel, expressed in sensory endings of proprioceptors innervating muscle spindles and Golgi tendon organs. Dominant PIEZO2 mutations were described in patients with distal arthrogryposis type 5 and Marden-Walker syndrome. Sensory ataxia and proprioception defect with dorsal column involvement together with arthrogryposis, myopathy, scoliosis and progressive respiratory failure may represent a distinct clinical phenotype, and indicate recessive mutations in PIEZO2.