Postpartum relapsing sensory neuritis responsive to intravenous immunoglobulin

Abstract

Sirs, Pure sensory vasculitic neuropathy has been described but is rare [2, 3]. Randomised controlled trial data is lacking, however treatment with various immunosuppressants has been suggested [1]. Postpartum relapses of sensory vasculitic neuropathy have not been described. We report a case of postpartum relapsing vasculitic sensory neuropathy exquisitely responsive to intravenous immunoglobulin (ivIg) with a benign course despite severe endstage features on nerve biopsy. A 27-year-old woman developed a rapidly progressive burning sensation in both feet during the seventh month of her second pregnancy. Two days following delivery of a healthy baby, she was unable to walk and required opiate analgesics for pain control. Examination revealed diminished pinprick and vibration in both feet as well as absent ankle reflexes, however wasting and weakness were not present. Nerve conduction studies (NCS) confirmed a distal sensory neuropathy. Investigations for systemic vasculitis were negative. The patient was given ivIg 0.4 g/kg/day for 5 days on six occasions 6 weeks apart. Her painful sensory symptoms started to improve and she was able to walk by the end of the first week of treatment. By the end of the second cycle of ivIg she was able to discontinue opiates. Subsequently there was gradual improvement in her symptoms, with complete resolution of symptoms by the end of the fourth cycle of ivIg. The patient remained well for 3 years but shortly after the birth of her third child the painful sensory symptoms recurred. Again, the patient’s symptoms responded well to six cycles of ivIg at a dose of 0.4 g/kg/day for 5 days at 6-weekly intervals, with a similar pattern of response as on the first occasion. Examination findings remain unchanged, without evidence of wasting or weakness. Sural nerve biopsy showed perivascular lymphocytic infiltration around in the epineurium with transmural migration of lymphocytes and partial obstruction of vessel walls (Fig. 1a, b). There was almost complete loss of myelinated fibres (Fig. 1c). The appearances were consistent with a severe end-stage vasculitic neuropathy. NCS were repeated 4 years after initial presentation and did not show any significant deterioration compared with the initial studies (Table 1). Distal, symmetric sensory neuropathy secondary to nonsystemic vasculitis [2] is rare but may show a benign course [3]. Randomised controlled trials of therapy in nonsystemic vasculitic neuropathy have not been carried out [3], but anecdotal case series suggest treatment with immunosuppressive therapies such as cyclophosphamide, azathioprine and steroids [1]. Postpartum relapsing vasculitic sensory neuropathy has not been described to our knowledge, although postpartum relapses have been described in systemic vasculitides [4]. This patient demonstrated a dramatic response to ivIg, with prolonged periods of remission after each course of treatment and has not accumulated any functional disability despite the severity of the nerve biopsy findings. She has elected not to have further children due to the perceived risk of relapse. S. M. Murphy (&) M. J. Hennessy Department of Neurology, Galway University Hospital, Newcastle Road, Galway, Ireland e-mail: smurph1@hotmail.com