Disabling Central Paroxysmal Positioning Upbeat Nystagmus and Vertigo Associated With the Presence of Anti-Glutamic Acid Decarboxylase Antibodies.

An immune attack by anti-glutamic acid decarboxylase (GAD) antibodies is believed to cause a deficiency in gamma-aminobutyric acid-mediated neurotransmission in the cerebellum. This, in turn, leads to several eye movement disorders, including spontaneous downbeat (DBN) and periodic alternating nystagmus. We describe a 68-year-old diabetic woman with disabling paroxysmal positioning upbeat nystagmus (UBN) exclusively in the supine position, associated with asymptomatic spontaneous DBN, alternating skew deviation and hyperactive vestibulo-ocular reflex responses on head impulse testing, in whom high titers of anti-GAD antibodies were detected. After treatment with intravenous immunoglobulin, a complete resolution of positioning UBN and spontaneous DBN occurred, along with a decrease in anti-GAD antibody titers. Positioning UBN in this case may reflect a transient disinhibition of the central vestibular pathways carrying posterior semicircular canal signals, due to lack of normal inhibitory input from the cerebellar nodulus/uvula. Immunoglobulin restored cerebellar inhibitory output, possibly by improving gamma-aminobutyric acid neurotransmission.

Multiple Trichoepithelioma Syndrome: A Case Report.

Multiple trichoepithelioma syndrome is a rare entity, and little is known about its epidemiological features. Patients usually present with multiple nonsuspicious skin lesions. Surgical excision is the mainstay of treatment, and diagnosis is usually made after the first pathology report. Once the diagnosis is established, patients are kept under clinical surveillance, and surgery is performed again if tumor burden and/or size justifies it. The authors present a male patient who presented to our outpatient clinic for the first time in 36 years without any relevant medical history, medication, or allergies. The patient had complaints of multiple skin lesions spreading across the head and neck regions. Surgical excision of the affected area and resurfacing using local advancement flaps were performed. Pathology reports were always consistent with trichoepitheliomas. No pathology of spiradenoma or cylindroma was ever reported. Usually, tumors are small enough for simple excision and primary closure. However, in the presented case, the size of the tumor and the involvement of central facial aesthetic units demanded a more complex approach.