Brain Pathology Case of the Month - March 2015

Contributed by Miguel A. Riudavets, MD1,5; María Laura Tallone, MD6; Jorge Correale, MD3; Fernanda Díaz, MD4; Gustavo Sevlever, MD, PhD1,2
Departments of 1Neuropathology, 2Research, 3Neurology, and 4Internal Medicine. Institute for Neurological Research, FLENI. Buenos Aires, Argentina.
    5Laboratory of Histopathology, OCME. Buenos Aires, Argentina.
    6Pathology Department, Hospital Santojanni. Buenos Aires, Argentina.


CLINICAL HISTORY

A 33 year-old patient with no relevant clinical history presented in August 2007 with right paravertebral rigidity. Patient had previously undergone kinetic physical therapy and been prescribed anti-inflammatory medication. In December 2007, patient presented to Neurology with right brachial paresis (3/5), positive osteotendinous reflexes, and cervical pain. MRI (Figure 1) showed a hyperintense intraspinal lesion on T2 sequence with contrast enhancement between C2-C7. Diffuse thickening of the spinal cord was also appreciated. January 2008: CSF showed high protein content, but was negative for oligoclonal bands. PCR for HSV and TB were also negative, as was serum NMO-IgG. Evoked potentials showed bilateral increase in latency (117.5 OD-115.5 OI). The condition was interpreted as myelitis. Patient began treatment with methylprednisolone (5 pulses), in spite of which medical condition worsened, developing nystagmus, muscle spasms, and progression of motor deficit with altered osteotendinous reflexes (February-March 2008). In March-April 2008, bilateral hand paresthesias, incontinence, severe right hemiparesis and sensory alterations were observed. In April 2008, patient was brought to our institution presenting bradycardia, hypotension (shock), and respiratory failure. Physical exam revealed flaccid tetraplegia, generalized areflexia, reactive isochoric pupils and horizontal nystagmus. Imaging revealed spinal lesion had increased in size and extended to the medulla (Figure 2). Anoxic-ischemic encephalopathy was diagnosed. Patient died in May 2008.

GROSS AND MICROSCOPIC PATHOLOGY

An acute necrotizing lesion of spinal cord and medulla, with sparing of adjacent neurons, was noted (Figure 3). The lesion also showed CD68 positive macrophages (Figures 3 and 4), and IgM deposits in blood vessel walls (Figure 5). In addition, another lesion was found in the cerebrum (right occipital white matter) (Figure 6). Optic chiasm presented no changes. The rest of the brain showed histological findings consistent with anoxic-ischemic encephalopathy.

FINAL DIAGNOSIS


International Society of Neuropathology