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Biomedical subjects

Sean J Pittock

Publications and source records attributed to Sean J Pittock.

26 records · Page 2Linked to original sources

Recovery of the upper limb post ischaemic stroke and the predictive value of the Orpington Prognostic Score.

OBJECTIVE: To document upper limb recovery in stroke patients and investigate whether the Orpington Prognostic Score (OPS) performed within 48 hours of admission to hospital post ischaemic stroke was a predictor of upper limb function at six months and two years. DESIGN: Inception cohort design. SETTING: Teaching Hospital. SUBJECTS: One hundred and fourteen patients hospitalized with acute ischaemic stroke were stratified into three groups based on their OPS within 48 hours of admission post stroke and underwent further assessments at two weeks, six months and two years after stroke onset. MAIN MEASURES: Rivermead Arm Score (RAS), Nine Hole Peg Test (NHPT) and grip strength (GS). RESULTS: Patients with a good OPS and intermediate OPS showed significant recovery in all outcome measures for up to six months post stroke (p < 0.05), while those with a poor OPS at 48 hours showed no significant improvement (p > 0.05). The OPS score at 48 hours was the most highly correlated variable with upper limb outcome at six months (r= -0.728) and at two years (r= -0.712) compared with other variables such as age, class of stroke, sensation, grip strength and RAS. CONCLUSION: Stroke patients demonstrate differential upper limb recovery patterns which need to be taken in consideration when designing studies that investigate efficacy of rehabilitation, and the OPS is highly correlated with upper limb recovery at six months and two years.

Aged↗

OKT3 neurotoxicity presenting as akinetic mutism.

BACKGROUND: Muromonab-CD3 (OKT3), a mouse monoclonal antibody directed against human T lymphocytes, is a potent immunosuppressive agent used to reverse and more recently to prevent allograft rejection, mostly in cardiac transplant recipients. Neurotoxicity from OKT3 usually manifests itself as a transient aseptic meningitis and remains uncommon. METHODS: The authors describe a dramatic neurologic syndrome after orthotopic heart transplant characterized by akinetic mutism, blepharospasm, anomic aphasia, and delirium. RESULTS: Magnetic resonance imaging (MRI) showed meningeal enhancement and single-photon emission computed tomography (SPECT) showed markedly reduced tracer uptake. Discontinuation of OKT3 resulted in resolution of this neuropsychiatric syndrome and reversal of abnormalities on neuroimaging that coincided with normalization of CD3+ lymphocyte count. CONCLUSIONS: In the initial posttransplant period, it remains difficult to attribute encephalopathic signs to toxicity of immunosuppressive drugs. However, MRI and cerebral perfusion studies may help support the diagnosis. More precise characterization of the prevalence of OKT3-associated encephalopathy could come from prospective SPECT studies.

Adult↗

Anti-neuronal nuclear autoantibody type 2: paraneoplastic accompaniments.

We identified the IgG autoantibody ANNA-2 ("anti-Ri") in 34 patients in a 12-year period by immunofluorescence screening of sera from approximately 75000 patients with subacute neurological disorders that were suspected to be paraneoplastic. Detailed clinical information was available for 28 patients (10 men, 18 women). Cancer was diagnosed in 24 patients (86%); 21 had histologically proven carcinoma (10 lung, 9 breast, 1 cervical, 1 bladder), and 3 had an intrathoracic imaging abnormality. Cancer anteceded neurological symptoms in 4 of 28 patients. Cancer detection frequency increased with continued surveillance. Neurological disorders, in decreasing frequency, were brainstem syndrome (including opsoclonus, myoclonus, or both), cerebellar syndrome, myelopathy, peripheral neuropathy, cranial neuropathy, movement disorder, encephalopathy, Lambert-Eaton syndrome, and seizures. Four patients had laryngospasm and four had jaw opening dystonia (two with neck dystonia). Nine (32%) were wheelchair-bound 1 month after neurological symptom onset. Most improved neurologically after immunomodulatory or tumor-directed therapy. Accompanying autoantibodies, found in 73% of sera, included ANNA-1, ANNA-3, CRMP-5-IgG, P/Q-type and N-type Ca(2+) channel antibodies, and muscle-type acetylcholine receptor antibody. Some neurological accompaniments of ANNA-2 may reflect potentially pathogenic humoral or cell-mediated responses to coimmunogenic tumor antigens, for example, Lambert-Eaton syndrome (P/Q-type Ca(2+) channel antibody) and peripheral neuropathy (ANNA-1 effector T cells).

Adult↗

The "spray can" sign: validation of a clinical observation in chronic inflammatory demyelinating polyneuropathy.

BACKGROUND: The presentation of chronic inflammatory neuropathies is variable. The decision regarding when to intervene with treatment is ideally determined by identifying early markers of loss of function. OBJECTIVE: To test the hypothesis that an observation of functional impairment, defined by a patient with demyelinating neuropathy, can be used as a reproducible and reliable measure of improvement with intravenous immune globulin. DESIGN: A 28-year-old woman presented with a chronic inflammatory demyelinating polyneuropathy. Her first complaint was the inability to use her deodorant spray because of hand weakness. A calibrated pincer gauge fixed on top of her usual spray can was used to objectively test finger flexion. Tip grip and lateral pinch were also measured. A calibrated dynamometer was used to measure grip strength. RESULTS: Power and precision grip force were reproducible in normal control subjects by means of the spray can test. This test proved to be a reliable indicator of reduced muscle strength in the patient and improved after treatment with intravenous immune globulin. CONCLUSIONS: The spray can test objectively quantified the daily function, nominated by the patient, of operating an aerosol can. This measurement, drawn from a functional loss observed by the patient, proved to be a portable and reliable indicator of decline and recovery in chronic inflammatory demyelinating polyneuropathy.

Adult↗

Reversible myelopathy in a 34-year-old man with vitamin B12 deficiency.

Vitamin B12 deficiency is common, with most patients lacking classic features of advanced severe deficiency. Early diagnosis and treatment prevent severe anemia and irreversible damage to the nervous system. We describe a 34-year-old man with pernicious anemia who presented with clinical and radiologic features of early myelopathy and borderline low serum levels of vitamin B12. Prompt diagnosis based on the measurement of serum methylmalonic acid and treatment with cyanocobalamin injections led to rapid resolution of clinical manifestations and magnetic resonance imaging abnormalities. We review the literature of magnetic resonance imaging in vitamin B12 deficiency myelopathy and discuss the issues relating to diagnosis and early treatment of this potentially reversible condition.

Adult↗

A serum autoantibody marker of neuromyelitis optica: distinction from multiple sclerosis.

BACKGROUND: Neuromyelitis optica is an inflammatory demyelinating disease with generally poor prognosis that selectively targets optic nerves and spinal cord. It is commonly misdiagnosed as multiple sclerosis. Neither disease has a distinguishing biomarker, but optimum treatments differ. The relation of neuromyelitis optica to optic-spinal multiple sclerosis in Asia is uncertain. We assessed the capacity of a putative marker for neuromyelitis optica (NMO-IgG) to distinguish neuromyelitis optica and related disorders from multiple sclerosis. METHODS: Indirect immunofluorescence with a composite substrate of mouse tissues identified a distinctive NMO-IgG staining pattern, which we characterised further by dual immunostaining. We tested masked serum samples from 102 North American patients with neuromyelitis optica or with syndromes that suggest high risk of the disorder, and 12 Japanese patients with optic-spinal multiple sclerosis. Control patients had multiple sclerosis, other myelopathies, optic neuropathies, and miscellaneous disorders. We also established clinical diagnoses for 14 patients incidentally shown to have NMO-IgG among 85000 tested for suspected paraneoplastic autoimmunity. FINDINGS: NMO-IgG outlines CNS microvessels, pia, subpia, and Virchow-Robin space. It partly colocalises with laminin. Sensitivity and specificity were 73% (95% CI 60-86) and 91% (79-100) for neuromyelitis optica and 58% (30-86) and 100% (66-100) for optic-spinal multiple sclerosis. NMO-IgG was detected in half of patients with high-risk syndromes. Of 14 seropositive cases identified incidentally, 12 had neuromyelitis optica or a high-risk syndrome for the disease. INTERPRETATION: NMO-IgG is a specific marker autoantibody of neuromyelitis optica and binds at or near the blood-brain barrier. It distinguishes neuromyelitis optica from multiple sclerosis. Asian optic-spinal multiple sclerosis seems to be the same as neuromyelitis optica.

Adult↗