2. Progression and Diagnosis
Two weeks later the patient was re-admitted with ataxia, gait
disturbance and loss of power bilaterally in her lower limbs. On
examination, power was 3/5 in both lower limbs and 5/5 in her upper
limbs. Tone was normal, sensation and reflexes were intact without
evidence of coordination deficits and an extensor plantar reflex. A
repeat MRI Brain and whole spine with contrast was negative for
leptomeningeal or parenchymal enhancement. Without a diagnosis and
progressive neurological deficits, a broader differential was conducted
to include nerve conduction studies, a repeat autoimmune, vasculitic and
viral screen, CT thorax, abdomen & pelvis, and serum ACE all of which
were non-diagnostic. Finally, a repeat LP with CSF immunophenotyping and
second MRI whole spine with contrast were ordered to exclude
infiltrative disease (Figure 1). This MRI result was discussed at three
major neuroradiology sites in our country to form a consensus on the
presence of infiltrative disease. Subtle posterior meningeal enhancement
involving the distal cord at T10 and T11 vertebral bodies was observed.
In the context of macroglobulinaemia, a bone marrow biopsy was performed
which showed a normocellular specimen with no evidence of lymphomatous
infiltration. While awaiting her CSF sample to return from flow
cytometry she deteriorated with ascending paralysis compromising
respiratory drive and requiring transfer to the intensive care unit
(ICU). The following morning, CSF immunphenotyping revealed a clonal
population of kappa light chains restricted B cells, which were CD5 and
CD10 negative, consistent with CNS involvement by lymphoma, in keeping
with a diagnosis of BNS.