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Motor ulnar neuropathy in diabetes
Societv Proceedings pocampal sclerosis, 30% of patients undergoing temporal-lobe surgery for epilepsy fail to become seizure-free. Incomplete resection and perioperative complications do not account for all failures. We postulated the presence of extrahippocampal cerebral structural changes in such patients, i.e. ‘dual’ pathology. Preoperative MRIs from 33 controls and 27 patients, with proven hippocampal sclerosis and complete hippocampal excision on postoperative MRI, were quantified to examine regional distribution of grey and white matter proportions, enabling identification and positioning along the anterior-posterior axis of subtle structural abnormalities. These were correlated with surgical outcome (mean follow-up 30.7 months). Twelve patients were not seizure-free. The presence of quantitative abnormalities in a given patient was significantly associated with a poor outcome in comparison to outcome in patients without such changes k2, P < 0.005). In most patients with quantitative abnormalities, these lay beyond the anterior-posterior extent of the diseased hippocampus or overlying lateral temporal neocortex. Widespread, occult extrahippocampal structural changes may explain surgical failure in these patients. Quantitation of preoperative MRI may supplement clinical decision making and prognostication in patients with a generally, but not inevitably, favourable outcome from epilepsy surgery; quantitation is applicable to other lesional epilepsy surgery. 4.
Paroxysmal alexia in reading epilepsy: ictal video EEG documentation, MRI and PET findings. - M. Koutroumanidis”, A. Agathonikou”, C.P. Panayiotopoulo@, A. Papadimitioub, S. Rowlinson” (aDepartment of Clinical Neurophysiology and Epilepsies, St Thomas’ Hospital, London. bDepartment of Neurology, Red Cross Hospital, Athens)
We present two male patients of normal intelligence with videoEEG documentation of ictal alexia elicited by reading. Case I started having paroxysmal alexia alone, or followed by right sided motor partial seizures, at the age of 16 years. Infrequent secondary generalised tonic clonic seizures (GTCS) also occurred with post-ictal aphasia. Video-EEG demonstrated high amplitude delta waves localised in the left mid to posterior temporal electrodes only with reading. Four seizures with ictal alexia occurred associated with slow rhythmic activity localised in the left mid/posterior temporal region. MRI showed an arachnoid cyst in the left temporal region. ‘8F-fluorodeoxyglucose-PET scan showed hypometabolism in the left mesial temporal lobe. Case 2 started having ictal alexia at the age of 22. Infrequent nocturnal GTCS also occurred. MRI and PET scans were normal. The ictal video-EEG showed paroxysmal 2 Hz waves followed by an alpha-like rhythm over the left mid to posterior temporal area. Two female patients with primary reading epilepsy and video-EEG confirmation of ictal jaw jerking are also presented. We conclude that paroxysmal alexia precipitated by reading is a manifestation of partial epilepsy and should be differentiated from primary reading epilepsy. Treatment is also different. 5.
The relationship between television frame rate and EEG abnormalities in patients with photo and pattern sensitive epilepsy. - G.F.A. Harding, F. Fylan, A. Edson (Department of Vision Sciences, Aston University, Birmingham)
We have previously suggested that the lesser incidences of photosensitive epilepsy in the USA may be related to the higher frame rate of their TV (60 Hz) to which fewer patients are sensitive (15%) in comparison to 50 Hz (49%). We investigated the probability of induction of EEG abnormalities by presentmg 35 patients with identical black and white patterns between 0.25 and 7 epd on two otherwise identical TV monitors whose frame rates were 50 and 100 Hz. The distance from the set was 1.5 m and the TV occupied a visual angle of 18” horizontally and 16” vertically. All patients showed abnormalities to 50 Hz TV but only 3 showed identical abnormalities to 100 Hz TV. Sixteen patients showed attenuated abnormality and a further 16 showed no abnormality (P < 0.0005). There was a clear interaction between abnormality elic-
35P
ited by 100 Hz TV and sensitively to intermittent photic stimulation at 50 Hz (P < 0.0005). This provides clear evidence that TV remains the most provocative factor in photosensitive epilepsy whether used for broadcast, video or electronic games material and indicates the value for patients in changing to 100 Hz frame rate TV sets. 6.
ulnar neuropathy in diabetes. - W. Schady, B. Motor Abuaisha, A.J.M. Bolton (Manchester Royal Infirmary, Manchester)
We have studied 20 diabetic patients with the clinical features of a motor ulnar neuropathy (16 men aged 39-77 years, 7 insulindependent, mean duration of diabetes 22 years). All but one had systemic complications, mostly severe: 10 amputees, 4 had had a renal transplant and two were blind. They all had a high Neurological Disability score. The onset of hand weakness and wasting was sudden in 5. often after an operative procedure. All patients had a classical ‘ulnar hand’ (bilateral in 15) but forearm muscles were little affected. Sensory loss was prominent in only half of the subjects. On nerve conduction studies, ulnar compound muscle action potentials (CMAP) were markedly reduced (mean 1.2 mV vs. 7.4 mV in controls) as were ulnar/ median ratios. Motor conduction was disproportionately slowed across the elbows, with or without conduction block, in 8/34 affected ulnar nerves. Five of these patients had a habit of leaning on their elbows and/or a Tinel’s sign. Median sensory action potentials were recordable in 12 patients but ulnar SAPS were absent in 30/34 affected nerves. Electromyography revealed advanced denervation in ulnar supplied muscles. We concluded that motor ulnar neuropathy is not uncommon in diabetic patients, especially those with severe systemic complications. Nerve entrapment at the elbow occurs in some, but in many cases the lesion is axonal and probably ischaemic. 7.
The role of afferent information in adaptation to altered visuomanual scaling during a two dimensional tracking task. J.D. Caleb, 0. Guedona, J.L. Vercher”, G. Gauthiera (“Universite de MediterranCe, Marseille, France. bUniversity of Southampton, UKb)
Seven control subjects and a man, IW, without large myelinated sensory afferents below the neck, were asked to follow the motion of a target on a TV screen by moving the unseen arm in a circular motion. Feedback, where allowed, was from superimposition of a cursor representing arm motion and position on screen. The results with feedback and no feedback of arm position relative to the target were found. Then the relationship between arm movement and its feedback was altered unbeknownst to the subject, so that in order to gain feedback of a circular movement on screen the arm actually had to move through an ellipse. The rate of adaptation to this distortion was recorded. Any plastic change in visuomotor scaling was then plotted by following arm motion, open loop, after 50 trials with the altered scaling. Control subjects, but not IW, showed plastic change after altered visuomotor scaling, so that their performance was relatively inaccurate at the end of the distorted trials. We conclude that peripheral afferents play a role in the plastic changes in motor programming that occur after alteration in visuo-manual scaling of arm movement. 8.
The pattern electroretinogram (PERG): a personal clinical review of 465 eyes. - G.E. Holder (Regional Department of Clinical Neurophysiology, Kings College Hospital, London and Electrodiagnostic Department, Moorfields Eye Hospital, London)
The findings from high contrast checkerboard PERG and pattern VEP are presented from 337 eyes with optic nerve demyelination, 90 eyes with optic nerve compression and 38 eyes with heredo-familial optic atrophy, and these are compared with those obtained in 175 eyes with dysfunction anterior to the retinal ganglion cells (retinal degen-
Paroxysmal alexia in reading epilepsy: ictal video EEG documentation, MRI and PET findings. - M. Koutroumanidis”, A. Agathonikou”, C.P. Panayiotopoulo@, A. Papadimitioub, S. Rowlinson” (aDepartment of Clinical Neurophysiology and Epilepsies, St Thomas’ Hospital, London. bDepartment of Neurology, Red Cross Hospital, Athens)
We present two male patients of normal intelligence with videoEEG documentation of ictal alexia elicited by reading. Case I started having paroxysmal alexia alone, or followed by right sided motor partial seizures, at the age of 16 years. Infrequent secondary generalised tonic clonic seizures (GTCS) also occurred with post-ictal aphasia. Video-EEG demonstrated high amplitude delta waves localised in the left mid to posterior temporal electrodes only with reading. Four seizures with ictal alexia occurred associated with slow rhythmic activity localised in the left mid/posterior temporal region. MRI showed an arachnoid cyst in the left temporal region. ‘8F-fluorodeoxyglucose-PET scan showed hypometabolism in the left mesial temporal lobe. Case 2 started having ictal alexia at the age of 22. Infrequent nocturnal GTCS also occurred. MRI and PET scans were normal. The ictal video-EEG showed paroxysmal 2 Hz waves followed by an alpha-like rhythm over the left mid to posterior temporal area. Two female patients with primary reading epilepsy and video-EEG confirmation of ictal jaw jerking are also presented. We conclude that paroxysmal alexia precipitated by reading is a manifestation of partial epilepsy and should be differentiated from primary reading epilepsy. Treatment is also different. 5.
The relationship between television frame rate and EEG abnormalities in patients with photo and pattern sensitive epilepsy. - G.F.A. Harding, F. Fylan, A. Edson (Department of Vision Sciences, Aston University, Birmingham)
We have previously suggested that the lesser incidences of photosensitive epilepsy in the USA may be related to the higher frame rate of their TV (60 Hz) to which fewer patients are sensitive (15%) in comparison to 50 Hz (49%). We investigated the probability of induction of EEG abnormalities by presentmg 35 patients with identical black and white patterns between 0.25 and 7 epd on two otherwise identical TV monitors whose frame rates were 50 and 100 Hz. The distance from the set was 1.5 m and the TV occupied a visual angle of 18” horizontally and 16” vertically. All patients showed abnormalities to 50 Hz TV but only 3 showed identical abnormalities to 100 Hz TV. Sixteen patients showed attenuated abnormality and a further 16 showed no abnormality (P < 0.0005). There was a clear interaction between abnormality elic-
35P
ited by 100 Hz TV and sensitively to intermittent photic stimulation at 50 Hz (P < 0.0005). This provides clear evidence that TV remains the most provocative factor in photosensitive epilepsy whether used for broadcast, video or electronic games material and indicates the value for patients in changing to 100 Hz frame rate TV sets. 6.
ulnar neuropathy in diabetes. - W. Schady, B. Motor Abuaisha, A.J.M. Bolton (Manchester Royal Infirmary, Manchester)
We have studied 20 diabetic patients with the clinical features of a motor ulnar neuropathy (16 men aged 39-77 years, 7 insulindependent, mean duration of diabetes 22 years). All but one had systemic complications, mostly severe: 10 amputees, 4 had had a renal transplant and two were blind. They all had a high Neurological Disability score. The onset of hand weakness and wasting was sudden in 5. often after an operative procedure. All patients had a classical ‘ulnar hand’ (bilateral in 15) but forearm muscles were little affected. Sensory loss was prominent in only half of the subjects. On nerve conduction studies, ulnar compound muscle action potentials (CMAP) were markedly reduced (mean 1.2 mV vs. 7.4 mV in controls) as were ulnar/ median ratios. Motor conduction was disproportionately slowed across the elbows, with or without conduction block, in 8/34 affected ulnar nerves. Five of these patients had a habit of leaning on their elbows and/or a Tinel’s sign. Median sensory action potentials were recordable in 12 patients but ulnar SAPS were absent in 30/34 affected nerves. Electromyography revealed advanced denervation in ulnar supplied muscles. We concluded that motor ulnar neuropathy is not uncommon in diabetic patients, especially those with severe systemic complications. Nerve entrapment at the elbow occurs in some, but in many cases the lesion is axonal and probably ischaemic. 7.
The role of afferent information in adaptation to altered visuomanual scaling during a two dimensional tracking task. J.D. Caleb, 0. Guedona, J.L. Vercher”, G. Gauthiera (“Universite de MediterranCe, Marseille, France. bUniversity of Southampton, UKb)
Seven control subjects and a man, IW, without large myelinated sensory afferents below the neck, were asked to follow the motion of a target on a TV screen by moving the unseen arm in a circular motion. Feedback, where allowed, was from superimposition of a cursor representing arm motion and position on screen. The results with feedback and no feedback of arm position relative to the target were found. Then the relationship between arm movement and its feedback was altered unbeknownst to the subject, so that in order to gain feedback of a circular movement on screen the arm actually had to move through an ellipse. The rate of adaptation to this distortion was recorded. Any plastic change in visuomotor scaling was then plotted by following arm motion, open loop, after 50 trials with the altered scaling. Control subjects, but not IW, showed plastic change after altered visuomotor scaling, so that their performance was relatively inaccurate at the end of the distorted trials. We conclude that peripheral afferents play a role in the plastic changes in motor programming that occur after alteration in visuo-manual scaling of arm movement. 8.
The pattern electroretinogram (PERG): a personal clinical review of 465 eyes. - G.E. Holder (Regional Department of Clinical Neurophysiology, Kings College Hospital, London and Electrodiagnostic Department, Moorfields Eye Hospital, London)
The findings from high contrast checkerboard PERG and pattern VEP are presented from 337 eyes with optic nerve demyelination, 90 eyes with optic nerve compression and 38 eyes with heredo-familial optic atrophy, and these are compared with those obtained in 175 eyes with dysfunction anterior to the retinal ganglion cells (retinal degen-