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Alberto J Espay

Publications and source records attributed to Alberto J Espay.

12 recordsLinked to original sources
PubMed2007

Unilateral versus bilateral tasks in early asymmetric Parkinson's disease: differential effects on bradykinesia.

Patients with Parkinson's disease (PD) have an impaired ability to perform two different simultaneous bimanual tasks. The differential effects of unilateral versus bilateral identical tasks on the bradykinesia scores of the more and less affected limbs in PD have not been examined. Twenty-seven patients with early and asymmetric PD underwent blinded, videotaped assessment, independently for each limb, using the bradykinesia items of the Unified Parkinson's Disease Rating Part III, Motor subscale (mUPDRS) and a Modified Bradykinesia Rating Scale (MBRS), which assessed amplitude, speed, and rhythm of movements. We found that the score for finger tapping in mUPDRS and MBRS, the score of amplitude of finger tapping in MBRS, and the lateralized scores of mUPDRS (sum of Items 23 to 25) of the most affected side significantly improved during the bimanual task. The improvement was associated with longer duration of illness, higher total scores in mUPDRS, and higher lateralized bradykinesia scores of the most affected side. There was a simultaneous deterioration of the lateralized bradykinesia scores in MBRS (sum of Items 23 to 25) and Item 25 of mUPDRS (rapid alternating movements) of the least affected side in bimanual tasks. In conclusion, identical bimanual tasks facilitate movement of the most affected side in early asymmetric PD at the cost of motor degradation in the least affected side. This observation also highlights the need to perform tasks of bradykinesia in one limb at a time for best accuracy.

Aged↗
PubMed2006

Anti-Hu-associated paraneoplastic limbic encephalitis presenting as rapidly progressive non-convulsive status epilepticus.

We report a 68-year-old woman who developed refractory non-convulsive generalized status epilepticus secondary to anti-Hu antibodies, detected by immunofluorescence and confirmed by Western immunoblotting. The patient presented with rapidly evolving impairment in consciousness and electroencephalographic evidence of lateralized pseudoperiodic sharp-wave discharges. Ataxia and sensory neuropathy developed within the first two weeks. To our knowledge, this is the first description of a very rapidly progressive non-convulsive status epilepticus of paraneoplastic origin. Serum anti-Hu antibodies deserve to be considered among the investigations required in the evaluation of rapidly progressive epileptic syndromes even when little or no imaging abnormalities are found.

Aged↗
PubMed2006

Motor cortex plasticity in Parkinson's disease and levodopa-induced dyskinesias.

Experimental models of Parkinson's disease have demonstrated abnormal synaptic plasticity in the corticostriatal system, possibly related to the development of levodopa-induced dyskinesias (LID). We tested the hypothesis that LID in Parkinson's disease is associated with aberrant plasticity in the human motor cortex (M1). We employed the paired associative stimulation (PAS) protocol, an experimental intervention involving transcranial magnetic stimulation (TMS) and median nerve stimulation capable of producing long-term potentiation (LTP) like changes in the sensorimotor system in humans. We studied the more affected side of 16 moderately affected patients with Parkinson's disease (9 dyskinetic, 7 non-dyskinetic) and the dominant side of 9 age-matched healthy controls. Motor-evoked potential (MEP) amplitudes and cortical silent period (CSP) duration were measured at baseline before PAS and for up to 60 min (T0, T30 and T60) after PAS in abductor pollicis brevis (APB) and abductor digiti minimi (ADM) muscles. PAS significantly increased MEP size in controls (+74.8% of baseline at T30) but not in patients off medication (T30: +0.07% of baseline in the non-dyskinetic, +27% in the dyskinetic group). Levodopa restored the potentiation of MEP amplitudes by PAS in the non-dyskinetic group (T30: +64.9% of baseline MEP) but not in the dyskinetic group (T30: -9.2% of baseline). PAS prolonged CSP duration in controls. There was a trend towards prolongation of CSP in the non-dyskinetic group off medications but not in the dyskinetic group. Levodopa did not restore CSP prolongation by PAS in the dyskinetic group. Our findings suggest that LTP-like plasticity is deficient in Parkinson's disease off medications and is restored by levodopa in non-dyskinetic but not in dyskinetic patients. Abnormal synaptic plasticity in the motor cortex may play a role in the development of LID.

Aged↗
PubMed2006

Cortical and spinal abnormalities in psychogenic dystonia.

OBJECTIVE: The pathophysiology of psychogenic dystonia has not been examined, but a growing body of literature suggests that abnormal sensory input from repetitive movements can lead to plastic cortical changes. Reduced cortical and spinal inhibition is well documented in organic dystonia. We tested the hypothesis that aberrant sensory input associated with abnormal posture may cause similar abnormalities by testing patients with psychogenic dystonia. METHODS: We assessed cortical and spinal inhibitory circuits and cortical activity associated with voluntary movement in 10 patients with clinically definite psychogenic dystonia, 8 patients with organic dystonia, and 12 age-matched healthy control subjects. RESULTS: Three measures of cortical inhibition, resting short- and long-interval intracortical inhibition and cortical silent period, were reduced in both psychogenic dystonia and organic dystonia. Cutaneous silent period mediated by spinal circuitries was increased in psychogenic and organic dystonia. Forearm spinal reciprocal inhibition was reduced in psychogenic dystonia. INTERPRETATION: Psychogenic and organic dystonia share similar physiological abnormalities. Previous findings of abnormal cortical and spinal excitability in organic dystonia may, in part, be a consequence rather than a cause of dystonia. Alternatively, these findings may represent endophenotypic abnormalities that predispose to both types of dystonia.

Adult↗
PubMed2006

Rapidly progressive sporadic dentatorubral pallidoluysian atrophy with intracytoplasmic inclusions and no CAG repeat expansion.

A 48-year-old man developed progressive hemidystonia and postural impairment with falls, followed by choreoathetosis, hyporeflexia, ataxia, supranuclear vertical gaze palsy, and dementia, lasting only 3.5 years from symptom onset to death. Family history and genetic testing were unrevealing. Neuropathology showed findings identical to genetic dentatorubral pallidoluysian atrophy (DRPLA), except for the absence of intranuclear inclusions and the presence of intracytoplasmic inclusions in the pons, striatum, thalamus, and subthalamic nucleus. This case expands the clinical and neuropathological spectrum of DRPLA and supports the hypothesis that aggregates may not be intrinsically pathogenic.

Disease Progression↗
PubMed2006

Rigidity and spasms from autoimmune encephalomyelopathies: stiff-person syndrome.

Stiff-person syndrome (SPS) is a disorder characterized by progressive muscle rigidity with superimposed painful muscle spasms and gait impairment due to continuous motor activity. Evidence has accumulated in favor of SPS representing an autoimmune, predominantly encephalomyelopathic disorder resulting from B-cell-mediated clonal production of autoantibodies against presynaptic inhibitory epitopes on the enzyme glutamic acid decarboxylase (GAD) and the synaptic membrane protein amphiphysin. Recognition of the clinical spectrum of SPS is important, particularly the upper-limb, cervical, and cranial nerve involvement that occurs in paraneoplastic variants. The correlation between antibody levels and severity of disease offers evidence for a pathogenic role for the anti-GAD and anti-amphiphysin autoantibodies. The scarcity of neuropathological correlates stand in sharp contrast with the severity of the disability in affected individuals and suggests that functional impairment of inhibitory circuits without structural damage is sufficient to develop the full clinical spectrum of SPS. The rarity of this condition limits the feasibility of controlled clinical trials in the treatment of SPS, but the available evidence suggest that drugs that increase cortical and spinal inhibition such as benzodiazepines and drugs that provide immune modulation such as intravenous immunoglobulin, plasmapheresis, and prednisone are effective treatments.

Autoantibodies↗
PubMed2006

Surgical treatment of movement disorders.

A substantial body of evidence has accumulated regarding the efficacy and safety of neurosurgery for Parkinson's disease, essential tremor, and dystonia. Surgery for movement disorders (thalamotomy, pallidotomy, and subthalamic nucleotomy or subthalamotomy) was largely ablative (lesion-based). Given the safety and anatomy-preservation advantage, long-term electrical stimulation of these same targets (thalamus, globus pallidus, and subthalamic nucleus) is discussed as the treatment of choice. High-frequency deep brain stimulation procedures replicate the effects of ablative interventions, but do not require making a destructive brain lesion. This article outlines patient eligibility for surgery, targeting techniques, intraoperative findings, and potential complications and discusses the outcomes expected for each of the major interventions for which clinical trial data are available.

Brain↗
PubMed2005

Atypical absences and recurrent absence status in an adult with Angelman syndrome due to the UBE3A mutation.

Angelman syndrome is a neurogenetic disorder resulting in refractory epilepsy and profound psychomotor retardation in its most prevalent form, caused by deletion of maternal chromosome 15q11-13. We report the case of a 29-year-old, mentally retarded man with unusual electroencephalographic changes during periods of atypical absence status epilepticus, a previously unreported manifestation of the usually milder, drug-responsive epilepsy associated with Angelman syndrome due to the UBE3A mutation.[Published with video sequences].

Adult↗
PubMed2003

Unique form of propriospinal myoclonus as a possible complication of an enteropathogenic toxin.

Propriospinal myoclonus is an uncommon form of spinal myoclonus propagated, presumably, by slowly conducting polysynaptic intraspinal pathways. Although most patients demonstrate no clear etiology, a variety of disorders have been linked to this abnormal movement, including trauma, multiple sclerosis, tumors, and infectious disorders such as herpes zoster, human immunodeficiency virus, and Lyme disease. We describe 2 young male patients from the same town in Northern Ontario, Canada, exposed to an outbreak of Escherichia coli O157:H7 from contaminated municipal water, who developed identical clinical and electrophysiological features suggestive of a rhythmic form of propriospinal myoclonus with activity alternating between abdominal and paraspinal muscles. A toxin-mediated microvascular thrombosis is proposed as a possible pathogenic mechanism underlying this novel association.

Adult↗
PubMed2002

Episodic coma in a new leukodystrophy.

Among the leukodystrophies of a hypomyelinating nature, childhood ataxia with diffuse central nervous system hypomyelination exhibits the unique feature of rapid decrease in mental status after relatively minor head injuries or otherwise noncomplicated febrile illnesses. This article reports the case of a child with progressive spastic quadriparesis in whom unconsciousness developed repeatedly as a result of minor head trauma and required prolonged critical-care nursing. Although cognition is believed to be relatively preserved in this disorder, this child developed progressive cognitive decline. A detailed review of the literature is presented along with discussion of the potential mechanisms of neurologic deterioration.

Aspartic Acid↗