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Objective: To describe a unique movement disorder and its clinical treatment response.
Background: Neuropathic tremor (NT) is a movement disorder typified by tremor occurring in the isolated context of peripheral neuropathy. Its phenomenology consists of a postural and/or kinetic tremor affecting the distal upper extremities with a typical frequency range between 3 to 6 Hz. The mechanism underlying NT is not well characterized and the etiology is broad, but there has been no clear relationship between neuropathy and tremor severity. It is estimated that 58% of patients with chronic inflammatory demyelinating polyneuropathy (CIDP) experience tremor, contributing to greater disability. NT responds to treatment of the underlying neuropathy in only a small number of cases.
Design/Methods: Video-case report.
Results: A 57-year-old, right-handed woman presented for further evaluation of tremor in the context of CIDP. Her neuropathy preceded the tremors by ten years and manifested with progressive sensory and motor deficits and sensory ataxia. Nerve conduction studies were remarkable for demyelinating sensorimotor polyneuropathy with serum studies identifying elevated titers of sulphated glucuronyl paragloboside (SGPG) antibodies. Her tremor affected the bilateral hands and was predominantly postural-kinetic, causing disability when eating, drinking and writing. The remainder of her exam was consistent with neuropathy. She had a robust, early response to treatment with intravenous immune globulin (IVIg) with waning of effect towards the end of each six-week cycle. She was also taking propranolol and primidone daily and this was unchanged during treatment.
Conclusions: We report a case of NT secondary to CIDP that had a robust response to treatment with IVIg. Response to treatment for neuropathic tremor is variable and better predictors of response to IVIg will need to be identified. The case and potential response predictors will be discussed.