Thomas Zambelis

Validation of the ABCD Score in Identifying Individuals at High Early Risk of Stroke After a Transient Ischemic Attack. A Hospital-Based Case Series Study

Background and Purpose— A simple score derived in the Oxfordshire Community Stroke Project (ABCD score) was able to identify individuals at high early risk of stroke after a transient ischemic attack (TIA) both in a population-based and a hospital-referred clinic cohort. We aimed to further validate the former score in a cohort of hospitalized TIA patients. Methods— We retrospectively reviewed the emergency room and hospital records of consecutive patients hospitalized in our neurological department with a definite TIA according to the World Health Organization (WHO) criteria during a 5-year period. The 6-point ABCD score (age [<60 years=0, ≥60 years=1]; blood pressure [systolic ≤140 mm Hg and diastolic ≤90 mm Hg=0, systolic >140 mm Hg and/or diastolic >90 mm Hg=1]; clinical features [unilateral weakness=2, speech disturbance without weakness=1, other symptom=0]; duration of symptoms [<10 minutes=0, 10 to 59 minutes=1, ≥60 minutes=2]) was used to stratify the 30-day stroke risk. Results— The 30-day risk of stroke in the present case series (n=226) was 9.7% (95% CI, 5.8% to 13.6%). The ABCD score was highly predictive of 30-day risk of stroke (ABCD=0 to 2: 0%, ABCD=3: 3.5% [95% CI, 0% to 8.2%], ABCD=4: 7.6% [95% CI, 1.2% to 14.0%], ABCD=5: 21.3% [95% CI, 10.4% to 33.0%], ABCD=6: 31.3% [95% CI, 8.6% to 54.0%]; log-rank test=23.09; df=6; P=0.0008; P for linear trend across the ABCD score levels <0.00001). After adjustment for stroke risk factors, history of previous TIA, medication use before the index TIA, and secondary prevention treatment strategies, an ABCD score of 5 to 6 was independently (P<0.001) associated with an 8-fold greater 30-day risk of stroke (hazard ratio, 8.01; 95% CI, 3.21 to 19.98). Conclusions— Our findings validate the predictive value of the ABCD score in identifying hospitalized TIA patients with a high risk of early stroke and provide further evidence for its potential applicability in clinical practice.

Essential trace element alterations in amyotrophic lateral sclerosis

Although trace elements have been implicated in the pathogenesis of amyotrophic lateral sclerosis (ALS) for a long time, new evidence has connected familial ALS with the metalloenzyme copper-zinc superoxide dismutase, thus reinforcing the study of their metabolism. This work presents the results of serum and cerebrospinal fluid levels of copper, zinc, manganese and magnesium, by atomic absorption spectrophotometry. Statistically significant decreased cerebrospinal fluid and serum copper levels were found in patients compared to the control group (20.25 +/- 7.09 vs. 30.86 +/- 16.02 SD micrograms/l and 913.21 +/- 165.55 vs. 1020.17 +/- 197.76 SD micrograms/l) while serum manganese levels were found to be increased in patients (3.59 +/- 0.89 SD micrograms/l) compared to controls (3.03 +/- 1.23 SD micrograms/l). Zinc and magnesium levels were unchanged. Our findings indicate an essential trace element imbalance in the disease.

Large and small fiber neuropathy in chronic alcohol-dependent subjects.

Abstract  The aim of the present study was to evaluate the occurrence of large and small fiber neuropathy among alcohol‐dependent subjects and to correlate neuropathy with the pattern of alcohol abuse, age of the subjects, nutritional status, and biochemical parameters. The study sample comprised 98 consecutive alcohol‐dependent subjects without signs of malnutrition treated for detoxification voluntarily in the specialized unit of the Athens University Psychiatric Clinic in an inpatient basis. Polyneuropathy (PN) was graded using the neuropathy symptoms score and neurologic disability score, conduction velocity studies, and quantitative sensory tests. Seventy‐seven men and 21 women aged 27–70 years took part in the study. PN was diagnosed in 57 subjects (58.2%). PN of both large and small fibers was found in 25 patients (25.5%); exclusively small fiber neuropathy was observed in 12 (12.2%) and exclusively large fiber neuropathy in 20 patients (20.4%). Neuropathy was significantly correlated with the age of the subjects, duration of alcohol abuse, liver dysfunction, macrocytosis, and blood sugar levels upon admission. PN was significantly more frequent in males than in females. The two groups of exclusively large and exclusively small fiber neuropathy did not differ significantly in any clinical and laboratory parameter. Subclinical neuropathy (stage 1) was observed in 11.2%, which also did not differ significantly in any clinical and laboratory parameter from the stage 2 PN group subjects. Our findings indicate the direct toxic effect of alcohol on peripheral nerve fibers as the main etiologic factor of alcoholic PN. Long‐standing hyperglycemia may be another contributing factor. Impaired vitamin B12 utilization may be also involved.

Impaired interhemispheric inhibition in amyotrophic lateral sclerosis

The pathogenesis of sporadic amyotrophic lateral sclerosis (ALS) remains unknown. Neurophysiological studies provide evidence of hyperexcitability of the motor cortex or of impairment of inhibitory intrahemispheric modulation of the corticomotoneuron in ALS. In this paper, we used TMS to elicit transcallosal inhibition of the motor cortex in ALS patients in order to investigate whether interhemispheric inhibitory mechanisms subserved by callosal fibres are also disturbed in ALS. Twenty‐five patients with ALS and 18 controls were recruited for the study. Resting Motor Threshold (RMT), Silent Period (SP) and interhemispheric inhibition (IHI) were recorded. No significant difference was detected regarding RMT or the duration of SP between patients and controls. IHI was detected in all controls. IHI was totally absent in eight patients, in another eight patients IHI did not reach a significant level and in the remaining nine patients was normal. The degree of IHI was significantly lower in ALS patients than in controls (p = 0.001). In conclusion, altered IHI in ALS patients is in line with the general pattern of reduced corticomotoneuron inhibition, being thus, one of the factors which may lead to chronic overexcitation of pyramidal cells.

Carpal Tunnel Syndrome: Associations between Risk Factors and Laterality

Aims: The investigation of the association between known risk factors and laterality in patients with carpal tunnel syndrome (CTS). Patients and Methods: 130 consecutive subjects with CTS only, or mainly, in the left hand were compared with 130 consecutive subjects with CTS only, or mainly, in the right hand. The following parameters were recorded: age, sex, job, handedness, hand mainly used in daily activities, BMI, diabetes mellitus, thyroid dysfunction, wrist trauma and connective tissue diseases. Results: A left dominant hand was independently associated with 13-fold higher odds for left-hand CTS, while a right dominant hand had 5-fold higher odds for right-hand CTS. Right-hand CTS was more frequent in younger subjects and females. Conclusion: Older age, higher BMI and diabetes mellitus were more prevalent in patients with bilateral CTS. Age and BMI were independently associated with bilateral CTS.

Dropped head syndrome as prominent clinical feature in MuSK-positive Myasthenia Gravis with thymus hyperplasia

MuSK-positive Myasthenia Gravis is in most cases clinically characterized by a progressive course with severe oculobulbar involvement or prominent neck, shoulder and respiratory muscle weakness. It is also distinguished from other forms of myastehnia through its lack of germinal centers or lymphocytic infiltrates in the thymic tissue. We present the case of a MuSK-positive female myasthenic patient with over four years slowly progressive weakness of the neck extensor muscles in the presence of thymus hyperplasia and discuss its uncommon and markedly focal clinical and electrophysiological features, as well as the excellent course under medication with pyridostigmine and prednisone, especially after thymectomy.

Repetitive Nerve Stimulation of Facial and Hypothenar Muscles: Relative Sensitivity in Different Myasthenia Gravis Subgroups

Aim: To assess the utility of repetitive nerve stimulation (RNS) in facial and hypothenar muscles in the clinical groups of myasthenia gravis (MG). Patients and Methods: We performed RNS study in the orbicularis oculi (O.O.), nasalis and abductor digiti quinti (ADQ) in 115 consecutive myasthenic patients and classified them according to the classifications of the Myasthenia Gravis Foundation of America. Patients were classified into three groups: group 1, group 2 (IIa, IIIa and IVa) and group 3 (IIb, IIIb and IVb). Results: RNS was abnormal in 95 patients (82.6%): 78.3% in the O.O., 66.1% in the nasalis and 19.1% in the ADQ. Both facial muscles were statistically more sensitive than the ADQ in all groups of patients. RNS in the O.O. was more frequently abnormal than in the nasalis only in group 1. Sensitivity to acetylcholine antibodies in myasthenic patients was 84%. Acetylcholine receptor (AChR) and muscle-specific tyrosine kinase antibodies were present in 96.7% of the patients with abnormal RNS in both facial muscles. Single-fiber electromyogram (SFEMG) was abnormal in 91.3% of the tested patients. One of the three tests used for the diagnosis of MG (AChR antibodies, SFEMG, RNS) was abnormal in 99.1% of the patients. Discussion: O.O. is the most sensitive muscle in all groups of MG followed by nasalis, while the ADQ is the muscle with the lowest sensitivity. Facial muscles, especially the O.O., should be the first to be tested in MG. The negativity of all tests (RNS, AChR antibodies, SFEMG) should question the diagnosis of MG, even in the presence of symptoms consistent with MG.

Urinary frequency in a case of Neuro-Behcet disease involving the brainstem—Clinical, electrophysiological and urodynamic features

Micturitional disturbances are reported in 5-20% of patients with Behcet disease (BD) affecting the central nervous system. However, corresponding data regarding urodynamic and electrophysiological findings are limited. A patient with known BD presented with dysarthria, diplopia and urinary frequency (36 times/day). MRI revealed an extensive lesion involving the lateral and tegmental pons, reaching the pontomedullary junction. Auditory evoked potentials indicated a left-side lesion between superior olivary nucleus and superior colliculus. Blink reflex examination indicated a location caudal to the left trigeminal root. Pudendal nerve somatosensory evoked potentials and transcranial magnetic stimulation of the perineal muscles were slightly affected. Bulbocavernosus reflex latencies were normal. EMG of the bulbocavernosus muscles showed a normal maximal voluntary contraction activity. Urodynamic studies revealed normal urine volume, maximum flow rate and residual volume. After intravenous administration of methylprednisolone diplopia and dysarthria resolved within 3 weeks. Urinary frequency remained almost unchanged for the first 8 weeks, but clearly improved during the following months. We assume that the present case of urinary frequency is the result of vasculitic lesion affecting the pontine micturition inhibitory area on the ground of Neuro-Behcet disease.

Botulinum toxin A in anti-GAD-positive stiff-limb syndrome.

tunnel. In most cases, pressure is translated to the proximal region, probably because the pressure gradient inside the tunnel is toward proximal. Pressure measurements have shown that the pressure maximum is at the distal carpal tunnel around the hook of hamate in some patients. We postulate that, in this case, with only distal nerve enlargement, the pressure maximum inside the tunnel is distal, resulting in nerve expansion at the exit. Nakamichi et al. described an hour-glass pattern of median nerve swelling (head– neck–body). The head was below the distal flexor retinaculum edge, the neck was at the hook of hamate (where the retinaculum is thickest), and the body was at the wrist crease (proximal to the pisiform bone). Our case is unique in showing swelling in only one direction: the head with no body. Nakamichi et al. also observed increased median nerve area within the carpal tunnel in patients with idiopathic CTS and thereby suggested that CTS is characterized by severitycorrelated intracarpal enlargement of the median nerve and not by compressive deformation. In our patient we did not observe intracarpal median nerve enlargement, but rather the size was toward the lower range of normal [cross-sectional area: 0.06 (right) and 0.05 (left)]. The median nerve often enlarges slightly just before it branches in normal individuals, although not to the extent described herein. Some earlier studies pointed out the technical difficulties associated with distal tunnel measurement; however, this may be overcome by adjusting the probe position and ultrasound beam intensity. Better-defined median nerve reference values at the distal carpal tunnel might further enhance sensitivity and specificity of diagnostic measurements. We propose that measuring median nerve enlargement at both ends of the carpal tunnel for CTS diagnostics may result in greater diagnostic sensitivity.

Motor and sensory polyneuritis with distal conduction failure as uncommon complication of an acute Rickettsia conorii infection

Rickettsia conorii is endemic in the Mediterranean region. Infections are mostly benign and neurological involvement is unusual. We describe a case of a man who presented with acute facial nerve palsy followed by flaccid tetraparesis due to an electrophysiologically established polyneuritis with distal conduction failure. Elevated IgM antibody titres for R. conorii were documented by indirect immunofluorescent antibody test. After doxycycline therapy, the patient presented a rapid clinical improvement. Repeated electrophysiological examinations revealed significantly restored compound muscles, and sensory action potentials, corresponding to the clinical course after treatment and ex juvantibus, indicate the causative relation between R. conorii infection and the described clinical syndrome.