Inflammatory sensory polyradiculopathy and reactivated peripheral nervous system infection in a genital herpes model

To study effects of herpesvirus reactivation on the nervous system, mice with latent genital herpes simplex virus type 2 (HSV-2) infections were immunosuppressed. Reactivated infection was detected by virus isolation or by antigen screening in histological sections of spines that contained cords, roots, and dorsal root ganglia. In ganglia, viral antigen was restricted to 2 distinct groups at T9-L2, and L6-S2 levels. In some ganglia, antigen was found in up to 4% of non-contiguous neurons, in their axons, and in endoneurial and satellite cells. Nerve roots distal to ganglia contained a few antigen-positive endoneurial cells and axons, but convincing antigen was not seen in proximal roots. Rare foci of anterior horn cells in the lower cord were the only central sites found to contain antigen. Comparison of antigen-containing ganglionic neuron counts to vaginal culture data indicate that peripheral virus shedding may depend on the number of neurons with reactivated infection. In non-immunosuppressed, latently infected mice, virus recovery was restricted to ganglionic explants from lower thoracic and lumbosacral regions; these ganglia contained no infectious virus in homogenates and no detectable antigen. These mice had an inflammatory polyradiculopathy in a similar distribution to virus found in latent and reactivated infection. The data show that genital HSV-2 infection can result in more extensive ganglionic latency and peripheral nervous system disease than has previously been recognized. Immunosuppression leads to reactivation and widespread, anatomically restricted antigen expression in many ganglia, consistent with the innervation of the genitourinary tract. Decalcified spine preparations provide a sensitive and simple way to detect virus reactivations and disease in these neural tissues.     

Psychometric evaluation of a new sensory scale in immune-mediated polyneuropathies. Inflammatory Neuropathy Cause and Treatment (INCAT) Group

OBJECTIVE: To perform a psychometric evaluation of the inflammatory neuropathy cause and treatment (INCAT) sensory sumscore (ISS) in sensory-motor immune-mediated polyneuropathies. This new sensory scale was evaluated to strive for uniformity in assessing sensory deficit in these disorders. METHODS: The ISS comprises vibration and pinprick sense plus a two-point discrimination value and ranges from 0 (normal sensation) to 20 (maximum sensory deficit). Before its clinical use, a panel of expert neurologists concluded that the ISS has face and content validity. The construct validity of the ISS was investigated by correlation and regression studies with additional scales (Nine-Hole Peg Test, 10-Meter Walking Test, a disability sumscore). All scales were applied in 113 patients with a stable neurologic condition (83 patients who experienced Guillain-Barre syndrome [GBS] in the past, 22 with chronic inflammatory demyelinating polyneuropathy [CIDP], 8 patients with a monoclonal gammopathy associated polyneuropathy), and 10 patients with recently diagnosed GBS or CIDP with changing clinical conditions. Reliability of the ISS was evaluated in the stable patients. Its responsiveness was investigated in the patients examined longitudinally. RESULTS: A moderate to good validity was obtained for the ISS (stable group: r = 0.38 to 0.56, p < or = 0.006; longitudinal group: R = 0.60 to 0.82, p < or = 0.007, except for the association with the 10-Meter Walking Test [p = 0.08]). Acceptable internal consistency, and inter- and intraobserver reliability were demonstrated for the ISS (alpha = 0.68 to 0.87; R = 0.85 to 0.89, p < 0.0001). Standardized response mean scores for the ISS were high (> or =0.8), indicating good responsiveness. CONCLUSIONS: All psychometric requirements are provided for the the inflammatory neuropathy cause and treatment sensory sumscore. The use of this scale is therefore suggested for bedside evaluation of sensory deficit in the individual patient with a sensory-motor immune-mediated polyneuropathy as well as in clinical trials.     

Recessive hereditary sensory neuropathy.

Clinical features in 2 cases of a recessive form of hereditary sensory neuropathy and the light and electron microscopy of sural nerve biopsy in 1 of them are described. The patients showed symptoms typical of this form of the disease; it should be stressed however that the loss of cutaneous sensation appeared to be limited to the distal parts of the lower extremities and involved all modalities of cutaneous sensation. Histological examination of sural nerve revealed a marked reduction in the number of myelinated fibres due to Wallerian-like axonal degeneration, of which various stages were represented. In addition, segmental demyelination, probably secondary to axonal changes, was seen. The unmyelinated fibres were also involved but to a lesser degree than the myelinated fibres. The observations indicate a progressive nature of the pathological process.     

Studies of sensory conductions. Comparison of latencies of orthodromic and antidromic sensory potentials.

Latencies of orthodromic and antidromic sensory potentials were compared in 16 normal median nerves. Peak latency was longer in the antidromic sensory response in every case. The peak latency of the antidromic sensory response depended on the distance between the recording electrodes; with shorter interelectrode distances it was similar to that of orthodromic sensory response.     

Inflammatory aneurysm due to neurocysticercosis.

A 69-year old man presented with a subarachnoid hemorrhage associated with a large intracerebral hematoma in the right temporal lobe. The oblique views of cranio-orbital computerized tomographic angiography (CTA) were suspicious for an aneurysm on a middle cerebral artery branch. At surgery, a cystic mass was found in the Sylvian fissure, associated with an aneurysm on a distal branch of the anterior temporal artery. The aneurysm was not situated at a bifurcation of the artery and was located beneath the cyst. It was secured by trapping. Pathological examination revealed that the cystic lesion was neurocysticercosis and that the aneurysm was inflammatory. We report a ruptured inflammatory aneurysm of a distal branch of the anterior temporal artery associated with neurocysticercosis, and present the histological findings. We believe this is the first report of such an inflammatory aneurysm with histological confirmation.     

Premonitory sensory phenomenon in Tourette's syndrome.

We administered a questionnaire designed to probe for premonitory sensations associated with motor tics to 50 patients with Tourette's syndrome (TS). Premonitory sensations were reported by 46 (92%) patients, and the most common sensation was an urge to move and an impulse to tic ("had to do it"). Intensification of premonitory sensations, if prevented from performing a motor tic, was reported also in 37 patients (74%), 36 patients (72%) reported relief of premonitory sensations after performing the tic, and 27 of 40 (68%) described a motor tic as a voluntary motor response to an involuntary sensation, rather than a completely involuntary movement. The "just right" sensation correlated with the presence of co-morbid obsessive-compulsive disorder. We conclude that premonitory sensations are an important aspect of motor tics and some patients perceive motor tics as a voluntary movement in response to an involuntary sensation.     

Gauging sensory representations in the brain.

The stream of information that enters a sensory system is a product of the ecological niche of an organism and the way in which the information is sampled. The most salient characteristic of this sensory stream is the rich temporal structure that is caused by changes in the environment and self motion of sensors (for example, rapid eye or whisker movements). In recent years, substantial progress has been made in understanding how such rapidly varying stimuli are represented in the responses of sensory neurons of a large variety of sensory systems. The crucial observation that has emerged from these studies is that individual action potentials convey substantial amounts of information, which permits the discrimination of rapidly varying stimuli with high temporal precision.     

Unusual glial cells in sensory ganglia.

Unusual glial cells not related with perikarya or fibres were observed with the electron microscope in dorsal root spinal ganglia. These interstitial cells were very electron dense, with big and irregularly shaped nucleus and scanty organelles. They occurred immersed in the endoneurial space tissue, with no basal lamina and presented no contacts with other cells. In addition to these interstitial cells present both in kittens and adult cats, younger kitten sensory ganglia contained refringent glial cells.     

Kindling in sensory systems: thalamus.

The kindling response of a number of thalamic (lateral and medial geniculate nuclei, posterior and lateral posterior nuclei) and midbrain (superior colliculus, reticular formation) sensory structures was assessed using a standard kindling paradigm in the rat, with repetition of the electrical stimulation once daily for between 100 and 200 days. This was compared with the kindling response of the hippocampus and dentate gyrus. Between 31 and 44% of animals with thalamic sensory placements developed generalized convulsions, whereas none with midbrain placements did so. The convulsions shared many of the basic properties of olfactory-limbic convulsions, but differed in various details, suggesting that a different neural mechanism was involved and that the thalamic sensory convulsions did not result from the spread of current to limbic structures. The results demonstrate that primary sensory structures in rat brain can be kindled.     

Hereditary sensory neuropathy and tonic pupils.

The clinical features of two siblings with both hereditary sensory neuropathy and bilateral tonic pupils are described. Other neurologic disorders associated with tonic pupils are reviewed. Our patients appear to represent a unique instance of the association of disorders that primarily affect the ciliary and dorsal root ganglia.     

Hereditary sensory neuropathy with spastic paraplegia.

Five cases of spastic paraplegia with a progressive symmetrical sensory neuropathy producing ulceration and osteomyelitis of the hands and feet are reported. The pathology in one patient, who died of secondary amyloidosis, was similar to that found by Denny-Brown in hereditary sensory radicular neuropathy with severe loss of posterior root ganglion cells and loss of myelinated fibres in both peripheral nerves and posterior columns of the spinal cord. A sural nerve biopsy in another case showed a striking loss of both myelinated and unmyelinated fibres, with some evidence of degeneration and regeneration. The inheritance is probably by an autosomal recessive gene. The prognosis in the more severe form of the disorder is poor.