[Scurvy in intensive care despite vitamin supplementation]. / Scorbut en soins intensifs malgré un apport vitaminique.

INTRODUCTION: Scurvy can occur in hospitalized patients despite vitamin supplementation. OBSERVATION: A 63 Year-old patient who had spent several weeks in intensive care developed an unexplained anemia and ecchymoses. Despite daily administration of 130 mg/day of vitamin C since his admission, his ascorbic acid blood levels had collapsed. Administration of 1g/day relieved the symptoms within four weeks. DISCUSSION: Whether a deficiency had existed prior to admission or not, scurvy developed during the week of intensive care despite parenteral nutrition supplying a daily dose of 130 mg of vitamin C. Such deficiencies decompensated in surgical situations remain a reality in developed countries. CONCLUSION: In certain pathological contexts and in all the growing number of cases in elderly patients and many surgical indications, the need for vitamin C supplementation has to be defined. The needs at that particular time must be taken into account and the prior nutritional status.

Abnormal involuntary movements induced by subthalamic nucleus stimulation in parkinsonian patients.

Chronic electrical subthalamic nucleus (STN) stimulation is under investigation for alleviating parkinsonian symptoms. STN alterations may carry the risk of provoking abnormal involuntary movements (AIMs). We took advantage of the reversibility of the stimulation technique to assess the possibility of inducing AIMs, using different electrical variables with or without concomitant levodopa intake. Above a given threshold voltage, stimulation could induce contralateral distal mobile AIMs or hemiballism in the off-drug condition in two patients. AIMs occurred after a latency that varied from a few minutes up to several hours after switching on the stimulator. Hemiballism immediately disappeared upon switching off the stimulator. In these patients, levodopa had never provoked that type of AIMs before surgery. Levodopa-induced AIMs were not modified by electrical stimulation, but off-phase dystonia disappeared in one patient. Stimulation of the STN induced AIMs that resembled both those observed following spontaneous lesions of the STN and levodopa-induced diphasic AIMs in parkinsonian patients. As electrical stimulation provoked AIMs and antiparkinsonian benefit occurred with different electrical variables and different timing, the mechanisms responsible for these two effects could be distinct.

Effect of parkinsonian signs and symptoms of bilateral subthalamic nucleus stimulation.

In monkeys rendered parkinsonian, lesions and electrical stimulation of the subthalamic nucleus reduce all major motor disturbances. The effect of electrical stimulation of the subthalamic nucleus was assessed in three patients with disabling akinetic-rigid Parkinson's disease and severe motor fluctuations. Quadripolar electrodes connected to a pulse generator were implanted in the subthalamic nuclei on both sides. Patients were evaluated with the unified Parkinson's disease rating scale and timed motor tests. 3 months after surgery, activities of daily living scores had improved by 58-88% and motor scores by 42-84%. This improvement was maintained for up to 8 months in the first patient operated upon. One patient was confused for 2 weeks after surgery, and another developed neuropsychological impairment related to a thalamic infarction which improved over 3 months. In one patient, stimulation could induce ballism that was stopped by reduction of stimulation. This is the first demonstration in human beings of the part played by the subthalamic nuclei in the pathophysiology of Parkinson's disease.

Acute and long-term effects of subthalamic nucleus stimulation in Parkinson's disease.

In animal models of Parkinson's disease (PD), it is postulated that the excessive output from the subthalamic nucleus (STN) plays a critical role. Selective lesions or high frequency electrical stimulation of the STN can alleviate parkinsonian symptoms in MPTP-treated monkeys. We decided to carry out STN stimulation in patients suffering from severe akinetic forms of PD. After approval of the institutional ethical committee, we operated on a parkinsonian patient aged 51, suffering for 8 years from a strongly disabling akinetorigid form of PD, complicated by an on-off effect (Hoehn and Yahr stage 5 in the worst-off motor phase). Stereotactic surgery was done on one side under local anesthesia. The theoretical target was chosen according to stereotactic atlases, based on ventriculographic landmarks such as anterior and posterior commissures (AC and PC). The final position of the chronic electrodes was optimized using electrophysiological recording and stimulation along with clinical assessment and surface EMG of agonist and antagonist muscles of the examined limbs. A spontaneous increase in neuronal activity was recorded in an area located 2-4 mm under the level of the intercommissural plane, 10 mm from the midline, at mid-distance between AC and PC. Within the same place, a 130-Hz stimulation induced acute and reversible akinesia alleviation mainly on the contralateral limbs, comparable to that obtained with dopaminergic drugs. No dyskinesia, such as hemiballism, was induced by introduction of electrodes or by stimulation. Then a long-term quadripolar DBS Medtronic electrode was inserted in this area. Studies of the effects of chronic stimulation were extensively performed to determine the best spatiotemporal and electrical stimulation variables.(ABSTRACT TRUNCATED AT 250 WORDS)

[Effects of the stimulation of the subthalamic nucleus in Parkinson disease]. / Effets de la stimulation du noyau sous-thalamique dans la maladie de Parkinson.

In Parkinson's disease, experimental studies favour a neuronal hyperactivity of the subthalamic nucleus. We carried out a subthalamic nucleus electrical stimulation in a patient aged 51, suffering for 8 years from a severe akineto-rigid form of Parkinson's disease, complicated with an on-off effect. Stereotaxic surgery was done under local anaesthesia on one side. Within the theoretical target, a 130 Hz stimulation induced akinesia alleviation mainly on the contralateral limbs. No abnormal movement was noticed. Then a long-term quadripolar DBS Medtronic electrode was inserted in that area. The study of the effects of chronic stimulation is in progress to determine the best temporal and electrical stimulation variables.

Chronic VIM thalamic stimulation in Parkinson's disease, essential tremor and extra-pyramidal dyskinesias.

Stereotactic thalamotomy of the VIM (ventral intermediate) nucleus is considered as the best neurosurgical treatment for Parkinsonian and essential tremors. However, this surgery, especially when bilateral, still presents a risk of recurrence and neurological complications. We observed that acute VIM stimulation at frequencies higher than 60 Hz during the mapping phase of the target suppressed the tremor of Parkinson's disease (PD) and essential tremor (ET). This effect was immediately reversible at the end of the stimulation. This was initially proposed as an additional treatment for patients already thalamotomized on the contralateral side, and then extended as a regular procedure for extra-pyramidal dyskinesias. Since January 1987, we implanted 126 thalami in 87 patients (61 PD, 13 ET, 13 dyskinesias of various origins). Deep brain stimulation electrodes were stereotactically implanted under local anaesthesia, using stimulation and micro-recording to delineate the best site of stimulation. Electrodes were subsequently connected to implantable programmable stimulators. The optimal frequency was around 130 to 185 Hz. The results (evaluated by a neurologist from 0 = no effect to 4 = perfect relief) are related to the type of tremor. Altogether, 71% of the 80 patients benefited from the procedure with grade 3 and 4 results. In 88% of the PD cases, the results were good (grade 3) or excellent (grade 4) and stable with time. Rigidity was moderately for a long improved but akinesia was not. The same level of improvement was observed in 68% of the ET patients and only in 18% of the other types of dyskinesias.(ABSTRACT TRUNCATED AT 250 WORDS)

La diatese homeopathique: realite biologique ou mythe historique? / Homeopathic diathesis: biologic reality or historical myth?

La diathese homeopathique est une notion actuellement controversee par certains courants et ecoles homeopathiques. Apres une longue pratique des "profils protidiques" l'auteur emet l'hypothese que les proteines plasmatiques sont peut-etre un des reflets de ce "mode reactionnel individuel" decrit par les homeopathes. Dans une vision globale plus philosophique que scientifique, cette etude fait remarquer que l'on peut comparer deux systemes au depart tres differents: d'un cote le "profil protidique" construit avec des parametres abstraits, et de l'autre la "diathese homeopathique" construite avec des parametres concrets. L'observation montre que les proteines plasmatiques s'organisent selon quatre etats qui rappellent les quatre diatheses homeopathiques. Ce travail tente de rehabiliter la notion de mode reactionnel individuel

[Treatment of Parkinson tremor by chronic stimulation of the ventral intermediate nucleus of the thalamus]. / Traitement du tremblement parkinsonien par stimulation chronique du noyau ventral intermédaire du thalamus.

Stereotactic ventral intermediate nucleus (Vim) thalamotomy may improve drug resistant severe parkinsonian tremor. However, tremor may recur and bilateral thalamotomy is known to induce unacceptable side effects in a proportion of patients. A high frequency (130 Hz) chronic Vim stimulation was performed in 4 parkinsonian patients, 2 of them having previously undergone a thalamotomy on the other side. Tremor was suppressed in all patients at the price of slight paresthesias. This improvement has been lasting from 2 to 14 months. Beneficial and adverse effects were suppressed at once each time the stimulation was stopped. These preliminary results are encouraging but a longer delay and more patients are obviously needed.

[Ataxic hemiparesis caused by a thalamic lacuna]. / Hémiparésie ataxique par lacune thalamique.

A 64 year old man was admitted for an ataxic hemiparesis. Magnetic resonance imaging (MRI) suggested a lacunar infarct. The lesion was located in the postero-lateral part of the contralateral thalamus, sparing the internal capsule.

[Left anterior choroidal artery syndrome with language disorders and constructional apraxia]. / Syndrome de l'artère choroidienne antérieure gauche avec troubles du langage et apraxie constructive.

The infarction in the territory of the anterior choroidal artery may induce a sensory motor impairment and neuropsychological symptoms close to those observed in some thalamic lesions. In a right handed man with a left sided infarction, language disturbances and constructional apraxia were observed. Cerebral blood flow measurements were performed 4 days after the stroke with the 133Xenon inhalation method. A decrease of mean hemispheric values was observed on both sides but more so on the left hemisphere, in the left frontoparietal regions. 98 days after the stroke language and constructional apraxia have partially improved. We have drawn a parallel between blood flow variations and neuropsychological signs. The cortical deafferentation caused by the interruption of the thalamo-cortical projections may explain the focalized decrease in cerebral blood flow values in the left hemisphere.