Neural Substrates for Hand and Shoulder Movement in Healthy Adults: A Functional near Infrared Spectroscopy Study

Characterization of cortical activation patterns during movements in healthy adults may help our understanding of how the injured brain works. Upper limb motor tasks are commonly used to assess impaired motor function and to predict recovery in individuals with neurological disorders such as stroke. This study aimed to explore cortical activation patterns associated with movements of the hand and shoulder using functional near-infrared spectroscopy (fNIRS) and to demonstrate the potential of this technology to distinguish cerebral activation between distal and proximal movements. Twenty healthy, right-handed participants were recruited. Two 10-s motor tasks (right-hand opening-closing and right shoulder abduction-adduction) were performed in a sitting position at a rate of 0.5 Hz in a block paradigm. We measured the variations in oxyhemoglobin (HbO₂) and deoxyhemoglobin (HbR) concentrations. fNIRS was performed with a 24-channel system (Brite 24®; Artinis) that covered most motor control brain regions bilaterally. Activation was mostly contralateral for both hand and shoulder movements. Activation was more lateral for hand movements and more medial for shoulder movements, as predicted by the classical homunculus representation. Both HbO₂ and HbR concentrations varied with the activity. Our results showed that fNIRS can distinguish patterns of cortical activity in upper limb movements under ecological conditions. These results suggest that fNIRS can be used to measure spontaneous motor recovery and rehabilitation-induced recovery after brain injury. The trial was restropectively registered on January 20, 2023: NCT05691777 (clinicaltrial.gov).

[Heart rate variability and vagal syncope in the young adult]

Heart rate variability is a sign of sympathetic activity. The authors compared two study populations of young males aged 19 to 30 years: population T comprised 15 healthy volunteers who had two negative tilt tests, one under basal conditions and the other after a bolus of isoproterenol; population S comprised 12 patients without cardiac or other disease, who were followed up for malaise and in whom the basal tilt test was positive, confirming the vagal origin of syncope. Temporal and spectral (total power, low frequency 0.04-0.15 Hz, hight frequency 0.16-0.40 Hz) data was obtained concerning heart rate variability from 24 hour Holter monitoring. The main difference between the two study populations was in the temporal data over 24 hours especially with respect to the heart rate (T = 73.5 +/- 6.9; S = 65.4 +/- 6.2/min; p = 0.004) and the percentage of successive R-R intervals varying by more than 50 ms (PNN 50) (T = 20.2 +/- 8.3%; S = 30.7 +/- 10.2%; p = 0.024). At night, the lowest SDANN/5 (standard deviation of RR intervals over periods of 5 minutes) were observed in group S (67.2 +/- 16.7 ms vs 87.3 +/- 24.4 ms; p = 0.026). No statistically significant differences between the two groups was observed in the spectral data. The temporal data of heart rate variability on Holter ECG monitoring over 24 hours could therefore have a good predictive value of the vagal origin of syncope in young adults.

Clinical and radiological aspects of dysplastic gangliocytoma (Lhermitte-Duclos disease): a report of two cases with review of the literature

Two cases of Lhermitte-Duclos disease confirmed by biopsy are reported. Review of the 58 published cases shows that the disease can manifest itself only by signs of increased intracranial pressure. Cerebellar symptoms are not constant. Computed tomographic (CT) scans suggest the diagnosis by showing a posterior fossa lesion, iso- and hypodense, partially calcified, and not enhanced by contrast medium. Magnetic resonance imaging (MRI) seems to define limits of the lesion better than CT scanning and could improve the surgical approach. Surgical excision of the lesion is the only satisfactory treatment. The postoperative prognosis is usually favorable.

Interobserver agreement in assessment of motor response and brain stem reflexes

In 1982, we developed a new coma scale, the Glasgow-Liège scale, which combines the quantified analysis of five brain stem reflexes with the Glasgow methodology. The present study was undertaken to determine to what extent agreement exists among different raters assessing brain stem reflexes (Parameter R) and to compare the results with those observed from motor responses (Parameter M). We show the good agreement achieved by different examiners in the evaluation of brain stem reflexes. Brain stem reflexes offer a slightly higher agreement (kappa = 0.69) than that of the study of motor response (kappa = 0.65). Within Parameters M and R, we observed less agreement in the evaluation of flexion responses and in the interpretation of oculocephalic reactions. The reliability of the evaluation of M and R parameters justifies the use of the Glasgow-Liège scale as a means for evaluating disturbances of consciousness.

Relative prognostic value of best motor response and brain stem reflexes in patients with severe head injury

The object of this study was to determine whether the addition of information on brain stem reflexes improves the prognostic precision of the Glasgow coma scale for patients with severe head trauma. The study is based on 109 patients with a Glasgow coma score of 7 or less during the first 24 hours after injury. The average age was 23 years. The patients were classified into three groups according to their actual outcome after 6 months: dead, 44 patients; persistent vegetative state and severe disability, 13 patients; moderate disability and good recovery, 52 patients. We then compared, by means of multiple group logistic regression, the prognostic ability of motor responses alone using the Glasgow criteria and of brain stem reflexes via an original approach. We showed that the predictive capabilities of brain stem reflexes were greater than those of motor responses. Although closely related (r = 0.68), the use of these two parameters in a single scale, the Glasgow-Liege scale, improves the precision of prognosis, especially for those head trauma patients with initial and complete loss of consciousness. Age was also revealed to be an important factor for outcome prediction.

[Initial clinical signs and results of surgical removal of cerebral arteriovenous malformations]

On the basis of 90 cerebral AVMs, the authors study clinical signs which show the AVM, before a dramatic bleeding. Such clinical signs are: benign subarachnoid hemorrhage or intracranial hypertension and, only for lobar AVMs, migraine, epileptic seizures, progressive neurological deficit. In such cases a misdiagnosis is avoided by CT Scan with contrast. In the second part, the authors show that the AVMs surgical removal gives better results than AVMs natural history studied over a 20 years period. Ten AVMs observed in deep coma died. Two surgical deaths are only observed out of 73 AVMs surgical removals. Out of 44 lobar AVMs totally removed, 37 show good results and seven disabilities. Out of 19 deep AVMs, 13 were totally removed and six partially. Such deep AVMs, especially AVMs of the corpus callosum or of lateral and third ventricles choroid plexus give excellent surgical results. The authors conclude that surgical removal is the safer treatment for the majority of AVMs (Acta neurol. belg., 1985, 85, 65-81).

One-stage excision of high-flow arteriovenous malformations

The authors describe two cases of high-flow arteriovenous malformations which illustrate a new technique to reduce the risk of brain swelling and diffuse hemorrhage during or after operation. This technique, used in the latter of the two cases, includes occlusion of the shunt, followed by the progressive tightening of a Selverstone clamp placed on the cervical internal carotid artery, lowering of the systemic arterial pressure, and the use of barbiturate anesthesia. Clamping and anesthesia are maintained for a 24-hour period after surgery.

[Incidence and treatment of subdural hygroma in severe head injuries]

In a population of 109 subjects with severe head injury (Liège score less than or equal to 12) we observed secondary development of subdural hygroma in sixteen patients. These liquefying processes were mostly secondary to the entry of CSF in the subdural space from tears in the arachnoid. Half the accumulations were accompanied by increased subdural pressure. Drainage of the subdural fluid brought clinical improvement in patients with elevated subdural pressure (greater than 15 torr).

Invading meningiomas of the sphenoid ridge

The authors report a series of 34 meningiomas of the sphenoid ridge. Eight tumors were totally removed uneventfully: two from the middle sphenoid ridge and six from the pterion or Sylvian point. Five tumors were not operated on because of their extensions or the patient's age. Twenty-one tumors raised serious surgical problems, resulting in a classification into three groups: deep or clinoidal, invading beyond the sphenoid wings, and a combination of both. Histological study of the hyperostotic bone showed meningiomatous cells in the bone in 12 of 13 cases so examined. Surgical limitations included invasion of the cavernous sinus (15 cases), of the dura mater of the sella turcica (seven cases), of the lateral part of the sphenoid body at the insertion point of the ala magna (seven cases), and of the common tendinous annulus of Zinn in the orbit (five cases), and basilar extracranial extension, particularly in the pterygomaxillary fossa (three cases). Following extensive removal, there were no early recurrences and three late recurrences (9 years and more). In 13 cases with a follow-up period of 1 to 8 years, there were no clinical recurrences. In only two cases was the meningioma totally removed. There were three postoperative deaths, two cases of hemiparesis with aphasia and epilepsy, one case with a frontal lobe syndrome, and nine with slight oculomotor, visual, or esthetic sequelae.

[Absence of signs of deconnection in four cases of partial anterior and median callosal lesions of vascular and neurosurgical origin (author's transl)]

Three cases of partial anterior and median callosal vascular lesions and one surgical case are presented. Some months later a neuropsychological examination did not show any signs of deconnection. Two interpretations are equally plausible: either the limited extension of the lesions as well as their location explain the absence of signs of deconnection, or these signs had existed but were regressive.

Surgery of the superior sagittal sinus in parasagittal meningiomas

The management of 21 parasagittal meningiomas is described; three were located in the anterior third of the sinus, 14 in the middle third, and four in the posterior third. Of these, four meningiomas were attached only to the lateral wall, two invaded the external layer of only one sinus wall, two involved the lateral recess of the sinus, and seven invaded one or two sinus walls. The remaining six tumors invaded the three walls of the sinus, which was completely blocked. There was bilateral meningiomas in four cases. Complete excision of the meningioma with preservation of the venous flow in the sinus and its collateral veins was attempted in each case. In the first eight cases it was possible to preserve the patency of the sinus without graft. In six of the next seven cases the removal of the two invaded walls permitted preservation of the third healthy wall and entailed the repair of the two involved walls by a partial graft, either dural graft (three cases) or venous graft (three cases). In one of the last six cases, a total vein graft was performed after complete excision of the invaded sinus. Two cortical veins were sutured to a collateral branch of the autogenous vein graft. The surgical technique of the partial and the total vein graft is described and clinical results and angiographic controls are discussed.

Surgical treatment of subdural effusions in infants

We puropose a simplified method for external drainage of subdural effusions in infants, not calling for a second operation to remove the catheters. This method allows the daily control of evacuated fluid, guarantees smooth and uninterrupted drainage, and permits analysis of the subdural collection. This operation which we would like to call external controlled drainage, does not call for parenteral feeding, but demands paediatric and neurosurgical collaboration. The method has no pretensions other than being simple, easy, and safe.

[Neurological complications of anticoagulants (author's transl)]

During a course of therapy by anticoagulants, 16 intracranial haemorrhages and 10 cerebral infarctions, were observed over a period of seven years. The intracranial haemorrhages include 11 subdural haematomas (four acute, seven chronic) and ive intracerebral haemorrhages, one of which resulted from the rupture of an arterial aneurysm. The anticoagulant therapy lasted in 12 cases for more than two years, and in four cases between twenty-four hours and two months. Monocoumarinics are most often the cause of the haemorrhages. The subdural haematomas are unpredictable and a traumatism was only observed in four cases. Three out of four patients with acute haematomas died, as well as two out of seven patients with chronic haematomas. Three out of four intracerebral haemorrhages occurred after ischemic cerebral accidents. The existence of a cerebral infarction counter-indicates the use of anticoagulants. The cerebral infarctions occurred five times during the anticoagulation therapy, and five times after stopping the treatment (from within a few days to a few weeks). Anticoagulation therapy, apart from infarction, is in general well supported and well supervised during the first weeks. Used for a long time, it may lead to very serious and often fatal complication, and must therefore be weighed against the advantages of the treatment.

[Unrecognized aneurysms of the circle of Willis]

The authors present, among 200 intracranial arterial aneurysms, 13 cases where the angiographic diagnosis of the aneurysm had been difficult. Among them, there were ten mistakes through default, and four mistakes through excess. Angiographic studies were done early, about the third day following subarachnoidal hemorrhage, so that conscious patients may have rapid surgery. The main diagnosis defaults were observed in aneurysms of the anterior communicating artery (cases 1, 2, 3, 4, 6), where the flexurae and arterial anomalies explain the diagnostic mistakes; double anterior cerebral artery, median anterior cerebral artery of Lazorthes, early origin of the frontopolar artery or of the callosomarginal artery. The aneurysms of the posterior wall of the carotid bifurcation, were hidden by this artery in the A.P. view and by the middle cerebral artery in the profile view (cases 5 and 7). Oblique views are necessary for the two localizations of these aneurysms. The middle cerebral aneurysms (case 8) may be hidden by a bony superposition. The Ziedses des Plantes subtraction method obviates this diagnostic default. Aneurysms of the peripheral branches of cerebral arteries (case 9) are filled later and slightly. Aneurysms of an artery less than 3 mm wide (posterior communicating artery, lenticular artery) are difficult to discriminate from their enlarged infundibulum (case 10). The small size of the aneurysm is not the only explanation of the difficult diagnosis. Indeed, few aneurysms are not evidenced by the first angiography, done at an early stage, even if any spasms exist. Only repeated angiographies could show the aneurysm particularly in young people. We repeat the angiography 15 to 20 days after the first one, and even some months later. In two young patients, angiographic studies were repeated a few times in three years and were normal; but after four years in one case and five years in the other, a new subarachnoidal hemorrhage occurred, and only then was the aneurysm shown by a new angiography (cases 4 and 5). In our series, the angiographic spasm could not afford an explanation for the diagnostic default. This, soon after the subarachnoidal hemorrhage, might be explained by the hemostatic clot which compresses or plugs the aneurysm. Further, the clot's lysis occurs, and the aneurysm can be evident. A double conlcusion must be drawn: --first, the angiography must be repeated if the image is dubious; the angiographic technique must be perfect and varied (oblique view, subtraction method, enlargement technique). Mistakes through excess, leading to useless operations, are as dangerous as mistakes through default; --secondly, great care should be exerted when reading and interpreting the X-ray films in the post-operative period in order to evaluate the surgical results, as well as in the preoperative period.

[Analysis of the results of nine-year experience in the surgical treatment of intracranial arterial aneurysm (author's transl)]

Two series of cerebral aneurysms are compared. The first was composed of 86 cases. The second, 73 cases, benefited from modern techniques, such as microscope, arterial hypotension, Yasargil's clips, bipolar coagulation, as well as from greater experience on the part of the surgical and anesthetic team. To avoid the risk of recurrent subarachnoidal hemorrhage, the surgical procedure has been done during the first week when consciousness is good or when corotid angiography shows a large cerebral hematoma. The surgical procedure is postponed if the patient shows a low state of consciousness or a cerebral vasospasm. In these cases, controlled external ventricular drainage improves patients' conditions and often allows for surgical intervention after three to five days. The Botterrel classification is used to evaluate the surgical results: good results were obtained in 71% of the entire series, as well as in 94% of grades 1 and 2 patients. The overall mortality rate was 15%. That for grades 1 and 2 was 2.7% and that for grades 1, 2 and 3 was 7.5%. The preoperative, operative and postoperative factors affecting results are discussed with particular attention to cerebral vasospasm and hydrocephalus.