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Biomedical subjects

Janet C Rucker

Publications and source records attributed to Janet C Rucker.

12 recordsLinked to original sources

Motor neuronopathy with dropped hands and downbeat nystagmus: a distinctive disorder? A case report.

BACKGROUND: Eye movements are clinically normal in most patients with motor neuron disorders until late in the disease course. Rare patients are reported to show slow vertical saccades, impaired smooth pursuit, and gaze-evoked nystagmus. We report clinical and oculomotor findings in three patients with motor neuronopathy and downbeat nystagmus, a classic sign of vestibulocerebellar disease. CASE PRESENTATION: All patients had clinical and electrodiagnostic features of anterior horn cell disease. Involvement of finger and wrist extensors predominated, causing finger and wrist drop. Bulbar or respiratory dysfunction did not occur. All three had clinically evident downbeat nystagmus worse on lateral and downgaze, confirmed on eye movement recordings using the magnetic search coil technique in two patients. Additional oculomotor findings included alternating skew deviation and intermittent horizontal saccadic oscillations, in one patient each. One patient had mild cerebellar atrophy, while the other two had no cerebellar or brainstem abnormality on neuroimaging. The disorder is slowly progressive, with survival up to 30 years from the time of onset. CONCLUSION: The combination of motor neuronopathy, characterized by early and prominent wrist and finger extensor weakness, and downbeat nystagmus with or without other cerebellar eye movement abnormalities may represent a novel motor neuron syndrome.

Anterior Horn Cells↗

Current Treatment of Nystagmus.

Acquired and congenital nystagmus often causes decreased visual acuity as a direct result of the inability to maintain stable foveal vision. In addition, acquired nystagmus causes a disabling subjective sensation of movement of the visual world called oscillopsia. The eye movements themselves do not require treatment if the patient is asymptomatic. However, therapy is necessary if visual disability is present. Treatments based in pharmacologic mechanisms are preferred. There are few controlled treatment trials and therapeutic efficacy generally is sought in a trial and error approach, depending on the type of nystagmus present. Treatment with 3,4-diaminopyridine and 4-aminopyridine recently have been shown to be effective for downbeat nystagmus. Gabapentin, baclofen, and clonazepam also are useful in some patients with downbeat nystagmus. Baclofen is the therapy of choice for periodic alternating nystagmus. Gabapentin often is effective for acquired pendular nystagmus. Clonazepam and valproate also may be effective for acquired pendular nystagmus. Memantine now is available in the United States and is promising in the treatment of pendular nystagmus. Optical devices that negate the negative effects of nystagmus continue to undergo development research. These and other medical, surgical, and optical devices are potentially useful alone or in combination with other therapies.

Journal Article↗

Binocular diplopia. A practical approach.

BACKGROUND: Diplopia is a common complaint in both inpatient and outpatient neurologic practice. Its causes are many, and special historical and examination features are important to localization and accurate diagnosis. REVIEW SUMMARY: This review is divided into 2 sections: the first related to diagnosis and the second to treatment of binocular diplopia. In the diagnostic section, emphasis is placed on identification of historical and examination features that can help to differentiate diplopia caused by dysfunction of cranial nerves versus neuromuscular junction, or orbital extraocular muscle. Techniques available to the neurologist for examining ocular motility and ocular misalignment and focused laboratory testing to evaluate diplopia are discussed in detail. The final section covers the various treatments for binocular diplopia, with recommendations regarding the utility of each treatment for different types of diplopia. CONCLUSIONS: A logical step-by-step approach applied to each patient with diplopia will help prevent misdiagnosis and improve patient care.

Cranial Nerve Diseases↗

Evaluating large saccades in patients with brain-stem or cerebellar disorders.

Clinicians conventionally test saccades at the bedside by noting the accuracy, initiation time, and speed of large movements, with the patient's head stationary. Partly for methodological reasons, laboratory analysis of saccades has mainly focused on movements of 20 degrees or less. By measuring the velocity waveform of large saccades, it is possible to examine more closely the way in which brain stem and cerebellum guide the eye to the target. Large saccades made by healthy humans show a positively skewed velocity profile. Slow saccades made by patients with brain-stem disorders show a prolonged plateau of low velocity. Some patients with cerebellar disorders may show increased acceleration and deceleration of saccades. Each of these velocity waveforms can be modeled by changing the parameters that describe medium-lead burst neuron firing. In certain other brain-stem and cerebellar disorders, transient decelerations or premature terminations of saccades occur; such velocity waveforms cannot be modeled solely by changing the parameters that describe burst neuron firing. Instead, it is necessary to postulate dysfunction of the mechanism that normally inhibits pontine omnipause neurons, thereby permitting burst neurons to discharge until the saccade is completed. Analysis of large, abnormal saccades calls for application of novel techniques to identify the beginning and end of the saccadic pulse command.

Adult↗

Abnormal eye movements predict disability in MS: two-year follow-up.

We conducted a two-year follow-up study of 40 patients with MS in whom we had reported that abnormal eye movements (AEM) were associated with greater general disability. AEM patients (17/40) remained significantly (p < .001) more disabled (median EDSS of 7.0) than those with normal eye movements (median EDSS of 5.0). AEM and great disability were associated with abnormal MRI signals in brainstem or cerebellum, where disease may involve control circuits for eye movements as well as descending motor pathways.

Adult↗

Internuclear ophthalmoparesis in episodic ataxia type 2.

Two patients sharing a novel mutation of the CACNA1A gene for P/Q calcium channels showed significant slowing of adducting saccades compared with normal subjects or patients with cerebellar disease. Internuclear ophthalmoparesis (INO) was clinically evident in one. While these findings might be specific to this mutation, INO in our patients with episodic ataxia type 2 suggested involvement outside the cerebellum, either in the brain-stem internuclear pathway or at the neuromuscular junction.

Adult↗

Ischemic optic neuropathies.

PURPOSE OF REVIEW: To review recent clinical data on ischemic optic neuropathies, which are some of the most frequently encountered optic neuropathies. These disorders include nonarteritic anterior ischemic optic neuropathy, arteritic anterior ischemic optic neuropathy, and posterior ischemic optic neuropathy. RECENT FINDINGS: Recent studies have facilitated our understanding of the natural history of visual loss, recovery, and recurrence in these disorders. Additionally, the value of various diagnostic techniques and treatment options, particularly for arteritic anterior ischemic neuropathy, has been clarified. SUMMARY: Application of the studies described in this paper should allow the clinician to more accurately diagnose ischemic optic neuropathies and counsel the patient with regard to appropriate management, prognosis for visual recovery and future risk of recurrence.

Adrenal Cortex Hormones↗

Anemia and papilledema.

PURPOSE: To elucidate the relationship between anemia and raised intracranial pressure (ICP). DESIGN: Interventional case series. METHODS: Retrospective case series and review of the literature. Only patients with documented papilledema, neuroimaging ruling out a space-occupying lesion, and anemia were included. RESULTS: Five women with confirmed idiopathic intracranial hypertension (IIH) (normal brain magnetic resonance imaging, normal cerebrospinal fluid, elevated intracranial pressure), and one man with presumed IIH (normal head computed tomography [CT], no lumbar puncture) were evaluated. All had bilateral papilledema associated with peripapillary hemorrhages. Two had retinal cotton-wool spots (CWS), and two had preretinal hemorrhages. All had severe iron deficiency anemia, which was discovered at the time of their ocular complaints in five of them. Their symptoms and signs improved dramatically after treatment of the anemia. We found 30 well-documented cases in the English and French literature. Among those, 13 were excluded from our analyses (11 had confounding disorders, and two had cerebral venous thrombosis). In the remaining 17 cases, isolated raised ICP associated with anemia was the most likely diagnosis, although in none of these cases was cerebral venous thrombosis excluded. CONCLUSIONS: Anemia may play a role in the occurrence of raised ICP and papilledema. Although only a few cases in the literature support this association, it may be more common than previously thought. Because most patients are not known to be anemic when papilledema is discovered, we suggest that a complete blood count be obtained in patients with IIH, especially in the absence of known associated factors such as obesity or medications or when treatment aimed at lowering ICP fails to improve the patient's symptoms. The underlying mechanisms remain unknown, but cerebral venous thrombosis should be carefully excluded.

Adult↗

Magnetic resonance imaging abnormalities in cat-scratch disease encephalopathy.

A 23-year-old woman who presented with a branch retinal artery occlusion followed by encephalopathy showed, by brain magnetic resonance imaging, a nonenhancing lesion in the right parietal gray matter with normal diffusion-weighted imaging. Of 64 reported cases of cat-scratch encephalopathy with documented neuroimaging findings, only 12 (18.8%) have had abnormal imaging findings. The abnormalities have included cerebral white matter lesions, basal ganglia and thalamic lesions, and multifocal lesions in immunocompromised patients, but no gray matter lesions similar to those in this patient. The variety of neuroimaging findings supports multiple pathophysiologic mechanisms of central nervous system involvement in this disorder.

Adult↗

Leptomeningeal enhancement and venous abnormalities in granulomatous angiitis of the central nervous system.

A 68-year-old woman with a relatively acute onset of right homonymous hemianopia, Gerstmann syndrome, and global cognitive failure was found to have a lymphocytic pleocytosis and elevated protein on spinal fluid examination and displayed marked meningeal enhancement on magnetic resonance imaging and dilated cortical venules on cerebral angiography. Brain and meningeal biopsy disclosed a necrotizing granulomatous inflammation of small and medium-sized subarachnoid vessels. The brain parenchyma was normal. The angiographic presence of venous abnormalities, the lack of observable angiographic arterial involvement, and the lack of parenchymal pathology are distinctly unusual in granulomatous angiitis of the central nervous system. This case, therefore, extends the pathologic and imaging spectrum of this disorder.

Aged↗