Facial nerve decompression for idiopathic Bell's palsy: report of 13 cases and literature review.

INTRODUCTION: The prognosis for cases of idiopathic facial palsy is usually good. However, some cases develop disabling sequelae, such as synkinesis or severe facial hemispasm, despite targeted medical treatment. OBJECTIVES: The authors try to achieve that electromyography is useful to identify patients with severe palsy and an unfavourable prognosis. These patients would probably benefit from facial nerve decompression. SETTING: The otolaryngology-head and neck surgery department of Pitié-Salpêtrière Hospital, Paris, a tertiary referral centre. PARTICIPANTS: Thirteen cases undergoing surgery between January 1997 and March 2007. MAIN OUTCOME MEASURES: We describe the electromyographic findings that led to surgery. All patients underwent surgery via a subpetrous approach, within four months of the onset of palsy. Decompression involved the first and second portions of the nerve and the geniculate ganglion. RESULTS: Recovery to House-Brackmann grade III was obtained in all cases at one year follow up. CONCLUSION: These results compared favourably with previous reports. A new therapeutic procedure may allow improved results.

[Congenital insensitivity to pain]. / L'insensibilité congénitale à la douleur.

Congenital insensitivity to pain (CIP) is a rare syndrome with various clinical expressions, characterized by a dramatic impairment of pain perception since birth. In the 1980s, progress in nerve histopathology allowed to demonstrate that CIP was almost always a manifestation of hereditary sensory and autonomic neuropathies (HSAN) involving the small-calibre (A-delta and C) nerve fibres which normally transmit nociceptive inputs along sensory nerves. Identification of the genetic basis of several clinical subtypes has led to a better understanding of the mechanisms involved, emphasizing in particular the crucial role of nerve growth factor (NGF) in the development and survival of nociceptors. Recently, mutations of the gene coding for the sodium channel Nav1.7--a voltage-dependent sodium channel expressed preferentially on peripheral nociceptors and sympathetic ganglia--have been found to be the cause of CIP in patients showing a normal nerve biopsy. This radical impairment of nociception mirrors the hereditary pain syndromes associated with "gain of function" mutations of the same ion channel, such as familial erythromelalgia and paroxysmal extreme pain disorder. Future research with CIP patients may identify other proteins specifically involved in nociception, which might represent potential targets for chronic pain treatment. Moreover, this rare clinical syndrome offers the opportunity to address interesting neuropsychological issues, such as the role of pain experience in the construction of body image and in the empathic representation of others' pain.

[Dystonia, tremor and repetitive instrumental use]. / Dystonies et tremblements d'utilisation instrumentale répétitive.

Three characteristic observations are presented along with three tables presenting 24 patients with the following elements in common: excessively repeated use of an instrument such as a pen, a musical instrument or a tool. The appearance after that use of a central pathological phenomenon that includes a local dystonia of a hand or the mouth, a tremor, or the association of a tremor and a dystonia, all within the muscular domain corresponding to that of the use. The discussion, which is based exclusively on the clinical findings, deals with the following elements: the role of the use of the instrument rather than task itself, the predominant pathogenic factor which is the repetitive action, to which is added a genetic component in one incompletely penetrant case of DYT 1, and a probable genetic susceptibility in the others. The absence of improvement with rest distinguishes this central pathology from rheumatologic or orthopaedic problems involving repetitive activities. The evolution is slowly declining when the responsible action is continued. This occurs in three stages: a specific disorder involving only the use of the particular instrument, a more enlarged involvement affecting other activities and eventually a dystonia associated with a tremor or a postural tremor always located to the initial area. The therapeutic interventions suggested by the pathologic role of the repetitive movement is: (1) to advise a new training for the instrument that excludes the habitual movement; (2) to advise the patient to vary any newly acquired repetitive movements.

Vivid dreams, hallucinations, psychosis and REM sleep in Guillain-Barré syndrome.

We conducted a prospective controlled study of the clinical and biological determinants of the mental status abnormalities in 139 patients with Guillain-Barré syndrome (GBS) and 55 patients without GBS placed in the intensive care unit (ICU controls). There were mental status changes in 31% of GBS patients and in 16% of controls (odds ratio = 2.3; P = 0.04). In GBS patients, they included vivid dreams (19%), illusions (30%, including an illusory body tilt), hallucinations (60%, mainly visual) and delusions (70%, mostly paranoid). They appeared a median 9 days after disease onset (range 1-40 days, during the progression or the plateau of the disease), and lasted a median 8 days. Seven (16%) patients experienced the symptoms before their admission to the ICU. Hallucinations were frequently hypnagogic, occurring as soon as the patients closed their eyes. Autonomic dysfunction, assisted ventilation and high CSF protein levels were significant risk factors for abnormal mental status in GBS patients. CSF hypocretin-1 (a hypothalamic neuropeptide deficient in narcolepsy) levels, measured in 20 patients, were lower in GBS patients with hallucinations (555 +/- 132 pg/ml) than in those without (664 +/- 71 pg/ml, P = 0.03). Since the mental status abnormalities had dream-like aspects, we examined their association with rapid eye movement sleep (REM sleep) using continuous sleep monitoring in 13 GBS patients with (n = 7) and without (n = 6) hallucinations and 6 tetraplegic ICU controls without hallucinations. Although sleep was short and fragmented in all groups, REM sleep latency was shorter in GBS patients with hallucinations (56 +/- 115 min) than in GBS patients without hallucinations (153 +/- 130 min) and in controls (207 +/- 179 min, P < 0.05). In addition, sleep structure was highly abnormal in hallucinators, with sleep onset in REM sleep periods (83%), abnormal eye movements during non-REM sleep (57%), high percentages of REM sleep without atonia (92 +/- 22%), REM sleep behaviour disorders and autonomic dysfunction (100%), reminiscent of a status dissociatus. The sleep abnormalities, that were almost absent in non-hallucinated GBS patients, were not exclusively related to ICU conditions, since they also appeared out of ICU, and were reversible, disappearing when the mental status abnormalities vanished while the patients were still in ICU. In conclusion, the mental status abnormalities experienced by GBS patients are different from the ICU delirium, are strongly associated with autonomic dysfunction, severe forms of the disease and possibly with a transitory hypocretin-1 transmission decrease. Sleep studies suggest that mental status abnormalities are wakeful dreams caused by a sleep and dream-associated disorder (status dissociatus).

[Post-irradiation neuromyotonia of the masseter muscle]. / Neuromyotonie post-radique du masséter.

INTRODUCTION: Neuromyotonia is a late and rare complication of radiation therapy, consisting of involuntary sustained muscle contractions with a delay in relaxation. OBSERVATION: We report the case of a 68-year-old man who developed neuromyotonia of the masseter muscle 6 years after irradiation for tonsil carcinoma. CONCLUSION: This observation underlines the importance of a correct diagnosis that can lead to an efficient treatment by carbamazepine.

[The hypolossal-facial anastomosis in man. A model for studying peripheral and central nervous system plasticity]. / L'anastomose hypoglosso-faciale chez l'homme: un modèle d'etude de la plasticité du système nerveux périphérique et central.

Hypoglossal-facial anastomosis (HFA) is a cross-over between the proximal stump of the hypoglossal nerve (XII) and the distal one of the facial nerve (VII). The hypoglossal axons regrow within the sheaths of facial fibres, allowing the progressive reinnervation of the facial muscles. This model is interesting to study some mechanisms of plasticity of the nervous system for several reasons: 1) It is a quite simple and reproducible model of pathophysiological state. It allows the study of 2) the modifications of the nervous system induced by the HFA, both upwards and downwards to the lesion and 3) the modifications of reflex activities involving intrapontine connections such as the blink reflex. The electrophysiological features of the trigemino-facial (TF) and trigemino-hypoglossal (TG) connections demonstrated that a central reorganisation of the blink reflex (BR) was induced by HFA: the afferent volleys of the TF and TH reflexes elicited by cutaneous and mucosal trigeminal afferents respectively have been shown to project onto common interneurones located within the trigeminal principal sensory nucleus. A long-term prospective study showed: 1) a reinnervation of the facial muscles by the hypoglossal axons is a necessary perequisite for the central reorganisation of BR, 2) a hyperinnervation of the facial muscles by the hypoglossal axons, 3) a transient and regressive cross-innervation of paralyzed face by the healthy contralateral facial nerve.

Cutaneous silent period in hand muscle is evoked by laser stimulation of the palm, but not the hand dorsum.

Painful electrical stimulation of the fingers evokes an inhibitory response in hand muscles (cutaneous silent period, CSP). The aim of this study was to determine whether purely nociceptive thermal stimuli applied to the hand evoke a CSP. High-intensity laser pulses (205 +/- 44 mJ) were delivered to the dorsum and palm of the hand in five volunteers. Electromyographic signals were recorded from the ipsilateral first dorsal interosseous muscle. We then compared the laser-evoked CSP with the CSP induced by electrical stimulation. A clear laser CSP (latency 90 +/- 7 ms) was evoked in all subjects when laser pulses were applied to the palm of the hand, whereas no response was recorded after stimulation of the dorsum. Electrical stimulation of both the dorsum and the palm evoked a CSP (latency 65 +/- 5 ms), although the reflex threshold was significantly lower after stimulation of the palm. This study confirms that the CSP is a nociceptive response specific to limbs that grasp. In humans, palm nociceptors are probably more functionally effective than dorsal nociceptors in inducing the hand-muscle inhibition that interrupts hand prehension (so that a potentially noxious source is dropped) before proximal muscles withdraw the limb.

Hypoglossal-facial nerve anastomosis: dynamic insight into the cross-innervation phenomenon.

The authors investigated the evolution of the dynamic features of the cross-innervation process in patients with complete facial palsy due to facial nerve transection during surgery for acoustic neuroma removal followed by a hypoglossal-facial nerve anastomosis (HFA). Clinical and electrophysiologic investigations were carried out before and over a 3-year period after HFA. Cross-innervation had started by the 10th day, progressed to the seventh to eighth month, then decreased and finally disappeared by the 12th month after HFA. Ipsilateral reinnervation was observed by the fourth month, progressed to the 12th to 18th month, and remained stable for the remainder of the follow-up period.

The phenomenology of body image distortions induced by regional anaesthesia.

Patients with peripheral nerve or spinal cord lesions frequently report perceptual distortions related to position, shape, texture or temperature of the affected areas. This study aimed to describe the phenomenology of such body image alterations during the course of upper limb, lower limb or spinal anaesthetic blocks in patients (n = 36) undergoing orthopaedic surgery. Multimodal sensory testing and assessment of motor function were performed at regular intervals, and the relationship between the reported body image distortions and the progression of sensory and motor impairment was analysed. We found that perceptual changes concerning the shape and size of the deafferented limb occurred in the great majority of patients. In all of them, illusions of swelling, elongation or shortening of the limb coincided with the impairment of warm, cold and/or pinprick sensations, suggesting that thin myelinated Adelta- and/or unmyelinated C-fibres may provide a source of tonic modulation to the limb's cortical representation. Such perceptual alterations of shape and size of body parts differed clearly from postural illusions in terms of frequency, time course and influence of vision. In addition to perceptual changes in the deafferented area, almost half of the patients felt their unanaesthetized lips and/or mouth swelling during the course of upper limb block, suggesting the unmasking of dynamic interactions between somatotopically adjacent cortical representations. Conflicting sensations could co-exist in the patient's body image, such as the illusion of swelling of a limb, which, at the same time, was felt to be missing. The sense of ownership of the deafferented limb was impaired in some cases. These observations show that the perception of body shape and the awareness of its postural variations are built from different plastic models. They also underline the contribution of peripheral afferent activity to the maintenance of a unified body image.

[Treatment of Bell's palsy with acyclovir and methylprednisolone]. / Traitement des paralysies faciales idiopathiques par méthylprednisolone et aciclovir.

OBJECTIVE: An open therapeutic trial was conducted in patients with Bell's palsy. Results were compared with data in the literature. MATERIALS AND METHODS: Between 1997 and 2000, 76 patients with Bell's palsy were treated with intravenous methylprednisolone (2 mg/kg/day) and acyclovir (5-10 mg/kg/8 hours) for 7 days. Treatment was initiated in all patients before the 14th day of illness. Severity of the palsy was scored on the first day of treatment and again one year later using the House and Brackman scale. RESULTS: Grade II or III palsy were observed in 38% of the patients at initial presentation, grades IV to VI in 62%. After treatment, 92% of the patients had reverted to grades I and II (good outcome) and only 8% had sequelae at 1-year follow-up. All patients with initial grade I or II recovered completely. For patients with grade IV, V, or VI complete recovery at 1 year was observed in 94, 86 and 50% respectively. CONCLUSION: Data in the literature suggest that corticosteroids should improve recovery in Bell's plasy. In our study, adjunction of acyclovir did not demonstrate any clear improvement in the cure rate. Benefit could depend on early prescription.

Mice transgenic for the human myotonic dystrophy region with expanded CTG repeats display muscular and brain abnormalities.

The autosomal dominant mutation causing myotonic dystrophy (DM1) is a CTG repeat expansion in the 3'-UTR of the DM protein kinase (DMPK) gene. This multisystemic disorder includes myotonia, progressive weakness and wasting of skeletal muscle and extramuscular symptoms such as cataracts, testicular atrophy, endocrine and cognitive dysfunction. The mechanisms underlying its pathogenesis are complex. Recent reports have revealed that DMPK gene haploinsufficiency may account for cardiac conduction defects whereas cataracts may be due to haploinsufficiency of the neighboring gene, the DM-associated homeobox protein (DMAHP or SIX5) gene. Furthermore, mice expressing the CUG expansion in an unrelated mRNA develop myotonia and myopathy, consistent with an RNA gain of function. We demonstrated that transgenic mice carrying the CTG expansion in its human DM1 context (>45 kb) and producing abnormal DMPK mRNA with at least 300 CUG repeats, displayed clinical, histological, molecular and electrophysiological abnormalities in skeletal muscle consistent with those observed in DM1 patients. Like DM1 patients, these transgenic mice show abnormal tau expression in the brain. These results provide further evidence for the RNA trans-dominant effect of the CUG expansion, not only in muscle, but also in brain.

Further evidence for a central reorganisation of synaptic connectivity in patients with hypoglossal-facial anastomosis in man.

In normal subjects, electrical stimulation of trigeminal mucosal afferents (lingual nerve - V3) can elicit a short latency (12.5+/-0. 3 ms; mean+/-S.D.) reflex response in the ipsilateral genioglossus muscle (Maisonobe et al., Reflexes elicited from cutaneous and mucosal trigeminal afferents in normal human subjects. Brain Res. 1998;810:220-228). In the present study on patients with hypoglossal-facial (XII-VII) nerve anastomoses, we were able to record similar R1-type blink reflex responses in the orbicularis oculi muscles, following stimulation of either supraorbital nerve (V1) or lingual nerve (V3) afferents. However, these responses were not present in normal control subjects. Voluntary swallowing movements produced clear-cut facilitations of the R1 blink reflex response elicited by stimulation of V1 afferents. In a conditioning-test procedure with a variable inter-stimulus interval, the R1 blink reflex response elicited by supraorbital nerve stimulation was facilitated by an ipsilateral mucosal conditioning stimulus in the V3 region. This facilitatory effect was maximal when the two stimuli (conditioning and test) were applied simultaneously. This effect was not observed on the R1 component of the blink reflex in the normal control subjects. These data strongly suggest that in patients with XII-VII anastomoses, but not in normal subjects, both cutaneous (V1) and mucosal (V3) trigeminal afferents project onto the same interneurones in the trigeminal principal sensory nucleus. This clearly supports the idea that peripheral manipulation of the VIIth and the XIIth nerves induces a plastic change within this nucleus.

A controlled study on the effects of transcutaneous electrical nerve stimulation and interferential therapy upon the RIII nociceptive and H-reflexes in humans.

OBJECTIVE: To study the effect of transcutaneous electrical nerve stimulation (TENS) and interferential therapy (IFT) upon the RIII nociceptive reflex and H-reflex. DESIGN: Double-blind conditions. PARTICIPANTS: Seventy healthy subjects were randomly allocated to one of seven groups (n = 10 per group): Control, TENS 1 (5 Hz), TENS 2 (100 Hz), TENS 3 (200 Hz), IFT 1 (5 Hz), IFT 2 (100 Hz), IFT 3 (200 Hz). INTERVENTION: In the treatment groups, stimulation was applied over the right sural nerve for 15 minutes. MAIN OUTCOME MEASURES: Ipsilateral RIII and H-reflexes were recorded before treatment, immediately after treatment, and subsequently at 25, 35, and 45 minutes. Subjects rated the pain associated with the RIII reflex using a computerized visual analogue scale (VAS). RESULTS: Statistical analysis using ANOVA showed no significant differences between baseline and posttreatment measurement for RIII reflex, H-reflex, or VAS data. CONCLUSION: These results suggest that neither type of electrical stimulation (TENS or IFT) affects the RIII or H-reflexes, at least using the parameters and application time in this study.

[True neurological thoracic outlet syndrome]. / Syndrome du défilé thoraco-brachial à forme neurologique.

The thoracic outlet syndrome (TOS) encompasses various clinical entities affecting the neurovascular bundle crossing the thoracic outlet. Unfortunately, this term often proves to be confusing because many of these entities have little in common beyond their known or presumed lesion site. Neurogenic TOS (true TOS) is caused by compression of the lower trunk in the brachial plexus, the cervical ribs or fibrous band. This syndrome is extremely rare. We consider that this neurological form of TOS is a clearly defined neurological syndrome. We report 10 patients with true TOS. All were females. Stating the onset was difficult because symptoms were progressive and insidious. Pain was the most frequently reported symptom. Sensory deficit was slight or absent. All patients showed unilateral severe atrophy of the thenar muscles. Wasting and weakness developed later. A reduced amplitude of ulnar and median compound muscle action potential associated with a normal amplitude of median sensory nerve action and a reduced amplitude of ulnar sensory nerve action potential were indicative of a chronic axon loss in the lower trunk of the brachial plexus. In all cases, we performed medial antebrachial cutaneous sensory nerve action potential, a C8-T1 innervated nerve. The absence of the medial antebrachial cutaneous sensory nerve action potential in 9 patients and a reduction in amplitude of 50 p. 100 compared to the unaffected side in the other patient, indicated the diagnostic value of this easy and reproductible test. It confirmed a C8-T1 post-ganglionic radicular lesion or a lower brachial plexus neuropathy. Radiography showed a rudimentary bilateral cervical rib or an elongated C7 transverse process in all cases. Surgery was performed in the affected side in 7 patients and in each case the lower part of the brachial plexus was found to be stretched and angulated over a fibrous band, which was removed. Pain was relieved after 1 to 4 weeks. A minimal motor improvement was observed after one year. Electrophysiological results were unchanged.

[Neurophysiological bases of the counterirritation phenomenon:diffuse control inhibitors induced by nociceptive stimulation]. / Bases neurophysiologiques du phénomène de contre-irritation: les contrôles inhibiteurs diffus induits par stimulations nociceptives.

To define the counterirritation phenomenon, we might refer to the Hippocratic aphorism: 'If two sufferings take place at the same time, but at different points, the stronger one makes the weaker silent'. On the basis of this clinically common observation, often used advantageously by the patients themselves, a number of therapeutic methods have been developed which are grouped under the terms counterirritation or counterstimulation. This phenomenon has not been scientifically analysed until recent years. Experimental results gathered during the last decade have shown that counterirritation phenomena have a well-defined neural substrate both in animals and in man. In particular, they have proved not to rely on segmental mechanisms, but rather imply spino-bulbo-spinal loops involving ascending pathways in the anterolateral spinal columns, integration in the lower brain stem, and descending influences reaching dorsal horn neurons via the dorsolateral quadrant. The results also suggest that the study of counterirritation is essential for accessing the physiology of nociception and pain control. The very existence of the counterirritation phenomenon is the easiest demonstrable index of a specific system for pain modulation in man. Besides its scientific interest, the elucidation of its neurophysiological bases has clinical importance, in as much as it may ameliorate our understanding of certain pain syndromes and contribute to the development of new investigative and therapeutic procedures.

Electrophysiological diagnosis of motor neuron disease and pure motor neuropathy.

Motor neuron disease (MND) is a group of disorders in which there is degeneration of upper and lower motor neurons to a variable degree. Amyotrophic lateral sclerosis is the most frequent form of the disease, presenting with both upper and lower motor neuron involvement. Frequently, especially in the early stages of the disease, only lower motor neuron signs are present. In these conditions, some pure motor neuropathies may resemble MND. The diagnosis is of importance because some of these motor neuropathies are "dysimmune" disorders and may respond to immune therapies. In such diseases the multifocal motor neuropathy with conduction block appears to be the more frequent. In MND and pure motor neuropathies, the electrophysiological examination is the most decisive test. In MND, it is of diagnostic importance. In addition, it is useful in the assessment of disease severity and progression, in the evaluation of therapeutic trials and in the understanding of etiopathogenesis of the disease. In pure motor neuropathies, the presence of conduction block leads to immune treatment with good response in more than 50% of the cases.

Painful and painless peripheral sensory neuropathies due to HIV infection: a comparison using quantitative sensory evaluation.

In order to characterize further, sensory disorders due to HIV-induced distal symmetrical polyneuropathy (DSPN), we compared quantitative sensory testing (QST) and electrodiagnostic parameters in patients presenting with painful or painless DSPN. Forty HIV patients with DSPN were studied and compared with ten seronegative control subjects: 15 patients presented with pains (spontaneous and/or evoked) in the lower limbs and 25 patients, matched for age, sex, duration of HIV and CD4 count, had non-painful symptoms (i.e. paresthesia). QST and nerve conduction studies (NCS) were performed on the lower limbs. von Frey hairs and a thermotest device were used to determine the mechanical- and thermal-, detection and pain thresholds. The responses elicited by suprathreshold thermal and mechanical stimuli were measured on a visual analog scale (VAS), to evaluate hyperalgesia. NCS were not significantly different between the two groups of patients. Thermal and mechanical detection thresholds, as well as the thermal pain threshold were significantly, and similarly, increased in both groups of patients as compared with the normal control subjects. Responses to suprathreshold thermal stimuli were similar in patients and control subjects. In contrast, mechanical pain thresholds were significantly decreased (mechanical allodynia) and responses to suprathreshold mechanical stimuli significantly increased (mechanical hyperalgesia) in the pain, but not in the painless patients. The intensity of mechanical allodynia/hyperalgesia was correlated with the intensity of spontaneous ongoing pain. We conclude that patients with DSPN are characterized by thermal, mechanical and electrophysiological deficits, suggestive of alterations in both small and large peripheral nerve fibers. Patients with a painful neuropathy present with static mechanical allodynia/hyperalgesia, suggestive of a selective alteration in the processing of mechanoreceptive signals, which might have a significant role in the pathophysiology of spontaneous and evoked pains in these patients.

Different effect of high doses of naloxone on spinal reflexes in normal subjects and chronic paraplegic patients.

There is still controversy over the effects of naloxone on spinal reflexes in view of the fact that both facilitatory and inhibitory activities have been observed. Dosage, supraspinal influences and interactions with different opiate receptors may account for the different findings. We investigated the effect of placebo (saline) and high doses of naloxone (1.66 mg/kg) on the monosynaptic (H reflex) and nociceptive polysynaptic reflex (RIII reflex) in five normal subjects and three chronic paraplegic subjects. Following the administration of naloxone, there were no changes in the RIII reflex threshold in either group. By contrast, there was a marked facilitation of the H reflex amplitude in the normal subjects, but not in the spinal cord-injured subjects after treatment with naloxone. Saline induced no changes in the RIII reflex threshold or the H reflex amplitude in either of the two groups. Our data suggest that under normal conditions the opiatergic modulation of the nociceptive reflex is not functionally active whereas the tonic inhibitory modulation of the monosynaptic reflex is mediated by descending pathways.