Clin Toxicol (Phila). 2011 Apr;49(4):334-6
Authors: Malkani R, Weinstein JM, Kumar N, Victor TA, Bernstein L
CONTEXT. Although neurological toxicity from elemental mercury vapor and organic mercury exposure has been commonly reported in the literature, it is rarely reported from soft tissue injection of elemental mercury. We present a case of neurological dysfunction from subcutaneous injection of elemental mercury. CASE DETAILS. A 35-year-old Latin American man subacutely developed gait ataxia, diplopia, and vomiting 1 year after subcutaneous injection of elemental mercury, a practice common in Afro-Caribbean and Latin-American cultures. Physical examination showed an indurated plaque on his right shoulder at the injection site, left third nerve and bilateral sixth nerve palsies, nystagmus, dysarthria, and gait and limb ataxia. The patient's serum and 24-h urine mercury levels were significantly elevated; he underwent excision of the mercury reservoir and chelation with dimercaptosuccinic acid but experienced only mild improvement after 1 year. DISCUSSION. Neurological sequelae from elemental mercury, specifically cognitive dysfunction, tremor, cortical myoclonus, and peripheral neuropathy, have been reported but cranial neuropathies, ataxia, cerebrospinal fluid pleocytosis, and the presence of anti-Purkinje cell type-Tr antibody have not. Treatment involves removal of any existing mercury reservoir and chelation; however, improvement in neurological dysfunction after treatment has rarely been reported in the literature.
PMID: 21563911 [PubMed - indexed for MEDLINE]
Pneumonol Alergol Pol. 2011;79(1):48-51
Authors: Raval D, Bernstein LP, Williams RE, Kuzniar TJ
Sleep disordered breathing (SDB) is frequently present in heart failure (HF), and it may take the form of obstructive (OSA) and central (CSA) sleep apnea. The use of continuous positive airway pressure (CPAP) in patients with OSA and HF is associated with an improved neuroendocrine profile and cardiac function. The degree of upper airway obstruction and the airway closing pressure (and the PAP pressure used to relieve it) may all be highly variable in a setting of uncontrolled HF, mostly due to variable airway oedema. We present a case of a man with HF whose cardiac symptoms radically improved after adequate treatment of his OSA with an auto-adjusting PAP device.
PMID: 21190153 [PubMed - indexed for MEDLINE]
Stereotact Funct Neurosurg. 2008;86(2):80-6
Authors: Novak KE, Nenonene EK, Bernstein LP, Vergenz S, Cozzens JW, Rezak M
BACKGROUND: Several subcortical structures have been targeted for surgical treatment of dystonia, including motor thalamus, internal segment of globus pallidus (GPi), and more recently, the subthalamic nucleus (STN). Deep brain stimulation of GPi is currently the preferred surgical treatment, but it is unclear if targeting other structures would yield better results. Patients who have already had a pallidotomy yet continue to experience dystonic symptoms may be limited in further treatment options.
METHODS: A patient with medically intractable, segmental, early-onset, primary torsion dystonia presented for surgical consultation after exhausting nearly all treatment options. Medications, botulinum toxin injections, cervical denervation surgery, and left-sided pallidotomy failed to give adequate relief. The patient was implanted with STN stimulating leads bilaterally according to standard procedures.
RESULTS: The patient received a 36% improvement in dystonic symptoms as measured by several dystonia rating scales. These benefits persisted for 2 years after surgery despite several hardware-related complications, and the patient reported being very satisfied with the outcome.
CONCLUSION: This result supports the efficacy of STN deep brain stimulation in dystonia patients, even those with prior pallidotomy.
PMID: 18073520 [PubMed - indexed for MEDLINE]
Mov Disord. 2006 Sep;21(9):1477-83
Authors: Novak KE, Nenonene EK, Bernstein LP, Vergenz S, Medalle G, Prager JM, Eller TW, Cozzens JW, Rezak M
Deep brain stimulation is generally a safe and effective method of alleviating motor impairment in advanced-stage Parkinson's disease patients. However, adverse events of surgery have been noted, such as hemorrhage, infection, seizures, and device failure. In this report, we describe 2 cases of the unusual adverse event of ischemia associated with subthalamic nucleus stimulator implantation. We present the intraoperative neurological symptoms, microelectrode recording data, imaging findings, and other correlated events. In the first case, the clinical effects of ischemia were evident intraoperatively and coincided with silence during microelectrode recording from the ischemic region. In the second case, the timing of the ischemic event could not be determined precisely but also was associated with a difficult mapping. Subcortical ischemia may be an underrecognized event that confounds neurophysiological mapping of deep brain structures and affects clinical outcomes.
PMID: 16721751 [PubMed - indexed for MEDLINE]
Arch Neurol. 2005 Jul;62(7):1150-3
Authors: Zeidman LA, Videnovic A, Bernstein LP, Pellar CA
BACKGROUND: HELLP syndrome (a combination of hemolysis, elevated liver enzyme levels, and low platelet count) is a severe variant of preeclampsia that generally occurs before delivery but can occur post partum. This syndrome is more common than eclampsia and frequently leads to devastating neurological consequences such as intracerebral hemorrhage.
OBJECTIVE: Although mentioned in the obstetric literature, there has been sparse reporting in the neurology literature specifically regarding intracerebral hemorrhage in HELLP syndrome. We illustrate such a case and review the existing literature regarding this severe complication.
SETTING: Obstetric unit at an academic medical center.
PATIENT: A 34-year-old primigravida experienced a pontine hemorrhage and subsequent respiratory arrest 22 hours after a normal delivery. This hemorrhage occurred 7 hours after the sudden onset of hypertension, severe headache, and intermittent abdominal pain.
RESULTS: Laboratory and postmortem evidence suggested HELLP syndrome with disseminated intravascular coagulation as the cause of her intracerebral hemorrhage.
CONCLUSIONS: Our case suggests the importance of the neurology consultant's familiarity with HELLP syndrome and the need for thorough laboratory testing and close monitoring in the puerperal patient with headache and hypertension.
PMID: 16009775 [PubMed - indexed for MEDLINE]
Am J Otol. 1997 Jan;18(1):86-92
Authors: Mhoon EE, Bernstein LP, Towle VL
HYPOTHESIS: The saccule provides important input for the otolith spinal reflex during sudden falls in the cat.
BACKGROUND: Previous studies on cats have identified two distinct components of muscle activity in response to sudden falls: an early otolith-dependent component (OSR) and a later nonlabyrinthine component associated with landing. The presence of an otolith-dependent reflex suggests a discrete role of the otolith organs in the control of posture and locomotion.
METHODS: The influence of saccular input on the OSR during sudden falls was studied by simultaneous video and electromyographic (EMG) recordings obtained from saccular-deficient deaf white cats and white cats with normal hearing.
RESULTS: A total of 628 sudden falls from five cats (two normal, one unilaterally deaf and two bilaterally deaf) were studied. Normal cats had a total of 337 drops, 276 of which (82%) were acceptable; a unilaterally deaf cat had a total of 79 drops, 56 of which (71%) were acceptable; deaf cats had a total of 212 drops, 177 of which (83%) were acceptable. The earliest of five observed behavioral events was that of forelimb extension which had a mean latency of 98 +/- 32 msec in normal cats and 139 +/- 28 msec in deaf cats (p < 0.0001). The mean latency of early EMG activity in normal cats was 19 +/- 7 msec and in deaf cats was 30 +/- 13 msec (p < 0.0001). The unilaterally deaf cat exhibited behavior and early EMG responses that were similar to those of normal cats. Deaf cats displayed poor body control during landings that improved with experience.
CONCLUSIONS: These data demonstrate that the saccule provides important input for the otolith spinal reflex in the cat, and cats that lack both saccules have discernible behavioral and EMG differences in response to sudden falls, when compared with normal cats.
PMID: 8989957 [PubMed - indexed for MEDLINE]
Electroencephalogr Clin Neurophysiol. 1989 Nov;73(5):419-26
Authors: Towle VL, Maselli R, Bernstein LP, Spire JP
Somatosensory evoked potentials, brain-stem auditory evoked potentials and electroencephalograms were obtained from 9 patients with the diagnosis of 'locked-in' syndrome. No pattern of evoked potential abnormality was specific to this syndrome, with findings ranging from bilaterally normal to unilaterally or bilaterally absent. The evoked potential studies complemented radiographic findings in defining the extent of the lesion and revealed that a portion of the pontine tegmentum was usually involved. Pathology from 2 patients corroborated the findings of the evoked potential studies. The value of evoked potential studies of patients with locked-in syndrome is to provide early objective evidence of brain-stem involvement independent of the clinical examination, EEG and radiographic studies.
PMID: 2479520 [PubMed - indexed for MEDLINE]
Neurosurgery. 1989 Sep;25(3):405-11
Authors: Warnke PC, Phillips A, Bernstein LP, Groothuis DR
We have developed a noninvasive method to determine the flow rates necessary to produce hyperosmotic blood-brain barrier disruption in individual animals. The method uses the intracarotid infusion of 0.9% NaCl at increasing flow rates, while concurrently measuring the amplitude of the somatosensory evoked potential (SSEP). For these studies, dogs were prepared with craniotomies to visualize the duration of cortical blanching. Saline (0.9% NaCl) was infused into the internal carotid artery at flow rates of 0.9 to 2.1 ml/s for periods from 2 to 40 seconds while the SSEP was concurrently measured in six 30-second epochs before, during, and after the infusion. There was a linear relationship between the duration of cortical blanching (from 2 to 30 seconds) and amplitude suppression of the major negative deflection of the SSEP. This relationship allowed us to predict the intracarotid infusion rate necessary to achieve cortical blanching for periods of 20 seconds or more. Subsequent infusion of 1.4 or 1.6 osmolar mannitol at the predicted flow rate resulted in more pronounced suppression of the SSEP than did 0.9% NaCl and produced disruption of the blood-brain barrier as documented by computed tomographic scans with contrast enhancement. Intracarotid infusions of 0.9% NaCl that produced partial blanching (partial replacement of blood in cortical vessels) were associated with paradoxical enhancement of SSEP amplitude, thus providing an additional measure of the adequacy of the infusion rate. This technique provides a reliable method to determine intracarotid infusion rates for hyperosmotic disruption of the blood-brain barrier in individual animals, before the intracarotid infusion of hyperosmolar solutions.
PMID: 2505161 [PubMed - indexed for MEDLINE]
J Neurosurg. 1989 Aug;71(2):266-72
Authors: Bailes JE, Cozzens JW, Hudson AR, Kline DG, Ciric I, Gianaris P, Bernstein LP, Hunter D
Studies on the peripheral nerves in rats and other species have helped in the development of laser-assisted nerve anastomosis (LANA), but offer little in evaluating the efficacy of this technique in primates. The authors present a study of LANA in the peripheral nerves of rhesus monkeys. Twelve adult rhesus monkeys underwent bilateral resection of a portion of the peroneal nerve followed by placement of autogenous sural nerve interposition fascicular grafts. The grafts were completed with conventional microsurgical suture technique on one side and with LANA on the other. At 5, 8, 10, and 12 months, the grafted nerves were evaluated for continuity, nerve conduction, and histology (both light and electron microscopy). No significant difference in continuity, conduction velocity, nerve degeneration, nerve regeneration, axon fiber number, or axon fiber density was found in any animal between grafts performed by conventional microsuture and LANA grafts. There was no difference in distal or proximal myelinated fiber density between the LANA grafts and the conventional microsuture grafts. It was concluded that LANA is as effective as microsurgical suture nerve anastomosis in a primate model of nerve repair and grafting.
PMID: 2664097 [PubMed - indexed for MEDLINE]
J Neurosurg. 1987 Oct;67(4):600-2
Authors: Eller TW, Bernstein LP, Rosenberg RS, McLone DG
A case of congenital tethered cervical spinal cord is presented in a young adult. Metrizamide computerized tomography was the most useful imaging technique for identifying the tethered spinal cord. Intraoperative somatosensory evoked potentials correlated well with clinical improvement following surgery.
PMID: 3309205 [PubMed - indexed for MEDLINE]