Spinal cord involvement and ganglionitis in leprosy

SV Khadilkar, PS Kasegaonkar, Meher Ursekar 
 Department of Neurology, Grant Medical College and Sir J J Group of Hospitals, Mumbai, India

Correspondence Address:
S V Khadilkar
Department of Neurology, Grant Medical College and Sir J J Group of Hospitals, Mumbai
India

Full Text

Sir,

We report an unusual case of leprosy to record the MRI changes of leprous ganglionitis and to newly document spinal cord involvement in leprosy,

A 20-year-old male presented with progressive loss of sensations and weakness of left hand of eight months duration. Examination showed a hypo-aesthetic patch on the dorsal aspect of the left elbow and left ulnar neuropathy involving sensory and motor functions. Left ulnar nerve was thickened at the elbow. A diagnosis of leprosy was made on clinical basis and he was started on Clofazimine, Rifampicin and Dapsone. He took treatment for three months and defaulted.

Two months after stopping therapy, he developed lightning pains affecting the medial aspect of the left arm and nape of neck. His clinical examination revealed involvement of the left ulnar and superficial branch of the left radial nerves, with loss of all sensory modalities including kinesthetic sensations. The electrophysiological findings are summarized in [Table 1].

Biopsy of the left superficial radial cutaneous nerve demonstrated acid-fast lepra bacilli by Fite Faraco Stain [Figure 1]. The MRI of the cervical spine showed abnormality within the left half of cervical cord at C5-6 level. The oval lesion exhibited a focal hyperintense central signal on T1W images within a larger area of T2W hyperintensity. It was mildly expansile. Associated findings were smooth thickening of ventral and dorsal roots on left side and enlargement with enhancement of left dorsal root ganglion at C5-6 level [Figure 2]A and B.

Leprosy mainly affects exteroceptive sensory modalities. Mononeuropathies and mononeuritis multiplex are the common presentations and polyneuropathy is rare. In a minority of patients, position and vibration may also be affected, resulting in a pan sensory neuropathy. [1] Such patients tend to have affectation of dorsal root ganglia. "Leprous ganglionitis" is believed to be responsible for the kinesthetic sensory deficits seen in these patients. [1] By histopathology of affected ganglia, various stages of neuronal degeneration, inflammation and acid-fast bacilli have been demonstrated. [2] In our case, MRI detected this uncommon involvement of dorsal root ganglia in a noninvasive manner. The intense enhancement of dorsal root ganglion is in keeping with active inflammatory process. Dorsal root ganglia may be affected in Sjogren's syndrome, HIV infection, other immunological and infective conditions and as paraneoplastic manifestation. [3] These conditions were not present in our patient.

Information on imaging of the spinal cord in leprosy is not available. In our patient, use of MRI technique helped us study the spinal cord and ganglia in the active phase of disease. Characteristics of MRI signals in the spinal cord suggest a granulomatous process. Autopsy studies of the spinal cord in patients with leprosy have shown changes of degeneration of posterior columns and amyloid bodies in grey and white matter, [4,[5] but not granulomas. We did not perform biopsy of the spinal cord lesion for concerns of safety and potential of reversibility.

This patient illustrates extensive involvement of the peripheral nervous system, dorsal root ganglia and also newly documents MRI changes of spinal cord involvement in leprosy.

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