Case 1. A 36 yo man had 3 weeks of dysphagia and confusion followed by acute encephalopathy, myoclonus, dysautonomia and diffuse pruritus.  He developed hypersalivation refractory to glycopyrrolate, scopolamine, atropine, submandibular gland resection and parotid gland botulinum toxin. The pruritus caused compulsive scratching leading to skin injury.  Brain and spine MRI, and body CT scan were normal. Cerebral PET showed decreased metabolism in the parieto-occipital cortex.  Lumbar puncture (LP) had 91 cells/mm³ (lymphocytic) and CSF-restricted oligoclonal bands. He had anti-glycine receptor alpha 1 antibodies in the serum and CSF.  Acutely, plasma exchange followed by intravenous immunoglobulin (IVIG) and cyclophosphamide led to mild improvement (ventilator dependent, following commands).  He was maintained on IVIG. Three years later, his modified Rankin Scale (mRS) was 3, pruritus and hypersalivation resolved.  

Case 2: A 42 yo man with recent gastrointestinal stromal tumor resection developed progressive vertigo, ataxia, bradykinesia, diplopia, dysarthria, dysphagia, dysautonomia, stiffness and myoclonus, as well as severe hypersalivation refractory to parotid gland botulinum toxin and glycopyrrolate. He progressed to wheelchair-dependence and anarthria. Brain and spine MRI, and body CT scan were normal. LP showed 98 cells/mm³  (lymphocytic), protein of 76 mg/dL, IgG index of 0.74 and CSF-restricted oligoclonal bands. CSF and serum were anti-GAD65 antibody positive. Treatment with high-dose steroids followed by plasma exchange and IVIG lead to stabilization. Maintenance rituximab improved dysautonomia, gait (walker), hypersalivation, and verbal output. 7 years later he had an mRS of 4.  

PERM can present with atypical symptoms including marked hypersalivation and pruritus. Clinicians should be aware of such symptoms since immunotherapy may stabilize symptom progression.