Biomedical subjects
Publications and source records attributed to D Lacomis.
Providing emotional support to caregivers is integral to comprehensive ALS care. The authors surveyed ALS Association centers and clinics and Muscular Dystrophy Association/ALS centers. Respondents thought that grief and bereavement support was integral to ALS care but thought that the support provided by their centers was often inadequate.
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Less invasive, inexpensive, and minimally time-consuming muscle biopsy techniques are desirable if their diagnostic yield is similar to that of open muscle biopsy. This article reviews the technique of semi-automated percutaneous needle muscle biopsy and its utility in diagnosis of neuromuscular diseases. Although direct comparisons with open biopsy are not available, the data indicate that percutaneous needle biopsy is quite useful for diagnosis of inflammatory as well as other forms of myopathy. The specimens can also be utilized for molecular diagnostic studies and cell culture.
OBJECTIVE: Stereotactic radiosurgical treatment of the proximal trigeminal nerve is used to relieve the pain of trigeminal neuralgia. The mechanism of the radiosurgical effect is not understood. METHODS: Two adult baboons underwent stereotactic magnetic resonance imaging-guided radiosurgery, using a gamma knife. A single 4-mm isocenter was targeted to each proximal trigeminal nerve, just anterior to the pons, to deliver a maximal dose of 80 or 100 Gy (total of four nerves). A nonirradiated baboon brain and nerves served as control specimens. Six months after treatment, magnetic resonance imaging was again performed and the brains and nerves were studied using light and electron microscopy. RESULTS: Magnetic resonance imaging indicated a 4-mm-diameter area of contrast enhancement at the target site in each nerve. All irradiated nerves exhibited axonal degeneration and mild edema at the target, with remnants of some myelinated axons. Large and small myelinated and unmyelinated fibers were affected. No inflammation was observed. Nerve necrosis was identified after 100-Gy treatment. The trigeminal ganglion appeared normal. CONCLUSION: Radiosurgery at 80 Gy causes focal axonal degeneration of the trigeminal nerve. At higher doses, partial nerve necrosis is observed. We think that these effects influence the physiological features of trigeminal neuralgia.
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Advances in molecular genetics are allowing better phenotype to genotype correlation of the non-dystrophic myotonic disorders. We report a 32-year-old woman, who first noted myotonia that was associated with weakness during her first pregnancy. The work-up disclosed that she had Thomsen's disease which is not known to be associated with weakness. In addition, her myotonia was of the fluctuating type and occurred (symptomatically) only during two pregnancies. We discuss the evaluation of myotonia in the pregnant woman which led to the diagnosis of Thomsen's disease and we conclude that in exceptional cases, fluctuating myotonia and weakness occurs in autosomal dominant chloride channel myotonia (Thomsen's disease).
OBJECTIVES: In general, large fiber sensory function is easier to assess than small fiber function both clinically and electrophysiologically. Therefore, small fiber sensory neuropathies are more difficult to diagnose. The relative sensitivities of different electrodiagnostic tests for small fiber neuropathy are not known. We sought to determine and compare the sensitivities of quantitative thermal sensory testing (QST), quantitative sudomotor axon reflex testing (QSART), and cardiovascular autonomic testing for diagnosis in patients with clinically suspected small fiber neuropathy. METHODS: 15 adult patients with clinically suspected small fiber sensory neuropathy underwent neurologic examination, QST, and QSART. Twelve also underwent cardiovascular autonomic testing. RESULTS: 80% had an abnormal neurologic examination consistent with small fiber neuropathy, while 93% had at least one abnormal quantitative test. QSART was most sensitive with 12 of 15 (80%) having abnormal studies while 10 of 15 (67%) had abnormal thermal thresholds by QST. Abnormal heart rate with deep breathing was detected in 9 of 12 (75%) patients. CONCLUSION: Of the modalities tested, QSART was most sensitive in confirming the clinical suspicion of a small fiber neuropathy. Autonomic cardiovascular abnormalities were also common in our patients. Clinical examination and QSART may be optimal for screening patients for small fiber neuropathy.
The spectrum of neuromuscular disorders among intensive care unit (ICU) patients has shifted toward disorders acquired within the ICU and away from "traditional" neuromuscular disorders that lead to ICU admission. We sought to assess this spectrum by determining the causes and relative frequencies of neuromuscular disorders that led to electromyography (EMG) examinations in our ICU population. Ninety-two patients were studied over a 4 1/2-year period. Twenty-six (28%) had neuromuscular disorders (mainly Guillain-Barré syndrome, myopathy, and motor neuron disease) that led to ICU admission. Among patients who developed weakness in the ICU, there was a predominance of organ transplant patients and patients with the systemic inflammatory response syndrome and multiorgan dysfunction. Thirty-nine (42%) developed acute myopathy (consistent with critical illness myopathy in most), and 13% developed acute axonal sensorimotor polyneuropathy (mainly critical illness polyneuropathy). Patients with acute myopathy and acute axonal sensorimotor polyneuropathy had similar functional outcomes. We conclude that among patients who underwent EMG in our ICU population, acute myopathy is three times as common as acute axonal polyneuropathy, and the outcomes from acute myopathy and acute axonal polyneuropathy may be similar.
Oculopharyngeal muscular dystrophy (OPMD) is a late adult onset, autosomal dominant muscular dystrophy characterized by ptosis and dysphagia. The OPMD gene has been localized to chromosome 14q11.2-q13 in French-Canadian pedigrees. We report 2 non-French-Canadian families with OPMD. Affected ancestors were immigrants to the United States from Italy and Normandy. The Norman pedigree does not share the French-Canadian haplotype. OPMD appears to be a heterogeneous disorder with similar phenotypes, but probably with different gene loci.
Mononeuropathies associated with orthotopic liver transplantation were evaluated in a prospective manner. Ten percent of liver transplant recipients were noted to have focal peripheral nerve lesions in the postoperative period. The ulnar nerve was most commonly involved, with intraoperative compression or postoperative trauma as possible mechanisms of injury. Other upper extremity mononeuropathies were likely a result of vascular cannulations. No brachial plexus injuries occurred. Diabetes and alcoholism were not risk factors for the development of a mononeuropathy.
Little is known about oxaluria-associated neuropathy, and no effective treatments have been described. We report two patients with clinically severe and progressive sensorimotor polyneuropathy associated with oxaluria. Electrodiagnostic testing and sural nerve histopathology revealed evidence of severe axon loss and demyelination. In addition, birefringent crystalline deposits were identified within endoneurial and perineurial blood vessel walls, axon cylinders, and perimysial blood vessel walls. Electron probe microscopy confirmed that calcium (consistent with calcium oxalate) was a major constituent of the crystals. Both patients had substantial improvement in neuropathic signs and symptoms after kidney and liver transplantations despite no prior improvement with hemodialysis. Our results confirm previous reports of a mixed axonal and demyelinating neuropathy with calcium oxalate deposition in association with oxaluria. In addition, our findings suggest that renal and liver transplantation may be potential treatments for the associated neuropathy.
Acute myopathy is a cause of weakness and additional morbidity in a variety of critically ill patients, including transplant recipients. We report the incidence of and risk factors associated with acute myopathy after orthotopic liver transplantation (OLTx). One hundred consecutive adult patients were prospectively assessed for muscle weakness after OLTx. Electrodiagnostic studies and muscle biopsies were performed on consenting affected patients. Potential risk factors for myopathy were evaluated in patients with myopathy versus control subjects. Seven patients developed acute persistent weakness after OLTx. Electrodiagnostic studies were consistent with a necrotizing myopathy. Histopathologic evaluation in five revealed a necrotizing myopathy with loss of myosin thick filaments. A higher initial index of illness severity, dialysis requirement, and higher doses of glucocorticoids were associated with development of myopathy. Patients with myopathy subsequently remained in the intensive care unit (ICU) longer than unaffected patients. In conclusion, acute substantial weakness was a source of additional morbidity in 7% of patients after OLTx. Most had myopathy with loss of myosin thick filaments. Patients with greater severity of illnesses and renal failure requiring dialysis were more likely to be affected. The effect of reducing exposure to corticosteroids in high-risk patients warrants further investigation.
Acquired (non-Wilsonian) hepatocerebral degeneration (AHD) is a rare irreversible neurologic syndrome that occurs in patients with chronic liver disease associated with multiple metabolic insults. The pathophysiology and the locations of the cerebral injuries are incompletely understood. We describe a patient with fatal hepatic cirrhosis and AHD in whom MR images showed abnormalities in the brachium pontis bilaterally. Neuropathologic evaluation disclosed multiple regions of subcortical spongiform white matter changes.
We evaluated 4 women with chronic fatigue and myalgias. Two had proximal weakness. All had elevated serum creatine kinase levels, but none was diagnosed with myopathy until electrodiagnostic studies revealed myotonic or complex repetitive discharges predominantly in paraspinal muscles. Histopathology of paraspinal muscles revealed vacuolar myopathies with glycogen storage; biochemical assays revealed phosphorylase deficiency in 1. Since vacuolar myopathies may affect paraspinal muscles more than limb muscles, electromyographic and histopathologic studies of paraspinal muscles may be required for diagnosis.
Vasculitis-associated neuropathy usually presents as multiple mononeuropathies or sensorimotor polyneuropathies that affect large nerve fibers; painful small fiber sensory neuropathy has not previously been described in association with vasculitis. This report describes 2 patients with small fiber neuropathy in whom vasculitis was found to be present. Patients with small fiber neuropathy for which no other cause has been identified should be evaluated for the presence of vasculitis.