Best Practice Recommendations for Stroke Patients with Dysphagia: A Delphi-Based Consensus Study of Experts in Turkey-Part I: Management, Diagnosis, and Follow-up.

Dysphagia is one of the most common and important complications of stroke. It is an independent marker of poor outcome after acute stroke and may become chronic after the acute period and continues to affect all aspects of the patient's life. Patients with stroke may encounter any of the medical branches in the emergency room or outpatient clinic, and as in our country, there may not be specialists specific for dysphagia, such as speech-language pathologists (SLP), in every hospital. This study aimed to raise awareness and create a common opinion of medical specialists for stroke patients with dysphagia. This recommendation paper has been written by a multidisciplinary team and offers 45 recommendations for stroke patients with dysphagia. It was created using the eight-step Delphi round via e-mail. This study is mostly specific to Turkey. However, since it contains detailed recommendations from the perspective of various disciplines associated with stroke, this consensus-based recommendation paper is not only a useful guide to address clinical questions in practice for the clinical management of dysphagia in terms of management, diagnosis, and follow-up, but also includes detailed comments for these topics.

Best Practice Recommendations for Stroke Patients with Dysphagia: A Delphi-Based Consensus Study of Experts in Turkey-Part II: Rehabilitation.

Dysphagia is one of the most common and important complications of stroke. It is an independent marker of poor outcome following acute stroke and it continues to be effective for many years. This consensus-based guideline is not only a good address to clinical questions in practice for the clinical management of dysphagia including management, diagnosis, follow-up, and rehabilitation methods, but also includes detailed algorithms for these topics. The recommendation paper has been written by a multidisciplinary team and offers 117 recommendations for stroke patients with dysphagia. While focusing on management principles, diagnosis, and follow-up in the 1st part (45 items), rehabilitation details were evaluated in the 2nd part (72 items).

Electrophysiological association of spontaneous yawning and swallowing.

Yawning and swallowing are fundamental physiological processes that are present from fetal stages throughout life and that involve sequential motor activities in the oropharyngo-larynx making it likely that they may share neuroanatomical pathways. We postulate that yawning and swallowing are controlled by a distributed network of brainstem regions including the central pattern generator of swallowing, and therefore spontaneous swallowing is frequently associated with spontaneous yawning. In this study, we sought to test this hypothesis by evaluating the elementary features of yawning in the facial, masseter and submental muscles, together with laryngeal movement sensor and respiratory recordings for spontaneous swallowing. We investigated 15 healthy, normal control subjects, 10 patients with Parkinson's disease (PD) and 10 patients with brainstem stroke (BSS). Apart from four subjects with PD and two with BSS, who had dysphagia, none of the other study subjects were dysphagic by published criteria. Twenty-five subjects (10 control, 10 BSS, 5 PD) were evaluated by 1-h polygraphic recording, and 10 (5 control, 5 PD) underwent whole-night sleep recordings. One hundred thirty-two yawns were collected, 113 of which were associated with spontaneous swallows, a clear excess of what would be considered as coincidence. The yawns related with swallows could be classified into the following three categories. The characteristics or the duration of swallows and yawns were similar between controls and disease subjects, with the exception of increased duration of yawning in subjects with BSS. Our findings support the presence of common neuroanatomico-physiological pathways for spontaneous swallows and yawning.

Electrophysiological Evaluation of Dysphagia in the Mild or Moderate Patients with Multiple Sclerosis: A Concept of Subclinical Dysphagia.

Swallowing mechanism and neurogenic dysphagia in MS have been rarely studied by electromyographical (EMG) methods. This study aims to evaluate the presence of subclinical dysphagia in patients with mild multiple sclerosis (MS) using electrophysiological methods. A prospective study of 51 patients with relapsing remitting multiple sclerosis and 18 age-matched healthy adults was investigated. We used electromyography to measure the activity of the submental muscles during swallowing. Electrophysiological recordings of patients were obtained during relapse, after relapse, and at any time in remission period. Clinical dysphagia was found in 12% of MS patients, while electrophysiological swallowing abnormalities were encountered in 33% of patients. Subclinical dysphagia was determined in 35% of patients during an MS relapse, in 20% of patients after a relapse, and in 25% of all 51 patients in the remission period based on EMG findings. Duration of swallowing signal of submental muscles in all MS patients was found to be longer than in normal subjects (p = 0.001). During swallowing of 50 ml of sequential water, the compensatory respiratory cycles occurred more often in MS patients than normal subjects, especially during a relapse (p = 0.005). This is the first study investigating swallowing abnormalities and subclinical dysphagia from the electrophysiological aspect in MS patients with mild disability. The electrophysiological tests described in this study are useful to uncover subclinical dysphagia since they have the advantage of being rapid, easy to apply, non-invasive, and without risk for the patients.

Orbicularis oculi muscle activation during swallowing in humans.

Intraoral trigeminal afferents elicit EMG activity from the lower facial muscle, orbicularis oris (OR) during swallowing. The upper facial muscles and especially orbicularis oculi (OC) were not previously known to be associated with deglutitional events. Nevertheless, given the large area of intraoral mucosa and teeth innervated by the trigeminal nerve afferents, a connection between OC motoneurons and deglutition may theoretically be expected, which we sought to evaluate in this study. Healthy controls were investigated for the possible synchronization of orbicularis OC and OR muscles during deglutition by the following methods: EMG activities were recorded during voluntary dry, 3-, 10-, 20-ml discrete wet swallowing, and sequential swallowing from a cup, concurrent with respiratory recording. A polygraphic recording was obtained from these muscles to determine whether they were synchronously activated during spontaneous swallowing. The polygraphic recording during spontaneous swallowing demonstrated that the OC and OR muscles were synchronously activated in all subjects. This synchronous activation was less prominent in voluntary discrete swallowing. It is proposed that this might be based on trigemino-solitarii-facial pathways with weaker connection to OC muscles. The synchronization of OC muscle activity with deglutition may be an evolutionary process that should be rudimentary in higher mammals including humans. The swallowing-induced cranial muscle activities could potentially explain some movement disorders, such as craniofacial dystonias.

Voluntary versus spontaneous swallowing in man.

This review examines the evidence regarding the clinical and neurophysiological differences between voluntary and spontaneous swallows. From the clinical point of view, voluntary swallow (VS) occurs when a human has a desire to eat or drink during the awake and aware state. Spontaneous swallow (SS) is the result of accumulated saliva and/or food remnants in the mouth. It occurs without awareness while awake and also during sleep. VS is a part of eating behavior, while SS is a type of protective reflex action. In VS, there is harmonized and orderly activation of perioral, lingual, and submental striated muscles in the oral phase. In SS, the oral phase is bypassed in most cases, although there may be partial excitation. Following the oral phase, both VS and SS have a pharyngeal phase, which is a reflex phenomenon that protects the upper airway from any escape of food and direct the swallowed material into the esophagus. This reflexive phase of swallowing should not be confused with SS. VS and SS are similar regarding their dependence on the swallowing Central Pattern Generator (CPG) at the brainstem, which receives sensory feedback from the oropharynx. There are differences in the role of the corticobulbar input between VS and SS.

Differential effects of peripheral vibration on motor-evoked potentials in acute stages of stroke.

OBJECTIVE: The excitability of sensorimotor cortex and spinal motoneurones can be modulated by afferent signals arising from the periphery. Low- and high-frequency vibrations activate separate classes of afferent units in the periphery. Low-frequency vibrations (2-100 Hz) activate the type I fast adapting afferent units (FA-I), whereas high-frequency vibrations (60-1000 Hz) preferentially activate the type II units (FA-II). Muscle spindles are also sensitive to high-frequency mechanical vibrations. Motor-evoked potentials (MEP) generated in response to transcranial magnetic stimulation (TMS) can be modulated by afferent signals. However, it is not clear whether these interactions take place at cortical or spinal cord levels. METHODS: Cerebrovascular attacks resulting in stroke generally affect both sensory and motor systems. In eight stroke patients with partial motor deficit in the first two weeks of the incident we studies the effects of low- (30 Hz) and high- (130 Hz) frequency mechanical vibrations on the MEPs obtained in response to TMS. Recordings from the abductor digiti minimi muscle were carried out by TMS of both lesioned and intact hemispheres. Six patients were tested again four to eight weeks after the initial assessment. The results also were compared with data obtained from eight control subjects. MEPs were evoked by 50% above threshold intensities and for each testing condition initially five control MEPs were recorded. This was followed by consecutive MEPs obtained during vibration (N= 5) and between vibrations (N= 5), and the traces were averaged and analyzed. RESULTS: In normal subjects both low- (30 Hz) and high- (130 Hz) frequency vibration resulted in shortening of MEP latencies. In patients, there was a similar effect on the affected side with 30 Hz, but not with 130 Hz. Stimulation of the intact hemisphere during high-frequency vibration in the second test revealed a latency shortening, which could be due to central reorganization. The amplitude of MEPs showed a stronger facilitation in the presence of low-frequency vibration in the early stage of stroke compared with normal subjects. However, in the second test the level of facilitation was reduced, indicating an effect at the cortical level. CONCLUSIONS: The results suggest that a cerebrovascular accident influences the modulatory effects of afferent inputs at both spinal and cortical levels, and in time, as reorganization takes place, these altered influences settle towards normal levels.

Human cremaster muscle and cremasteric reflex: A comprehensive review.

OBJECTIVE: Human research on the cremaster muscle (CM), cremasteric reflex (CMR) and genitofemoral nerve (GFN) and reports on their clinical applications using electrophysiological and histological techniques are rare. We aimed to present a detailed review of the human CM and CMR based on our earlier publications and relevant literature. METHODS: Electromyography (EMG) of the CM was recorded using disposable needle electrodes. CMR was obtained with tactile and/or electrical stimulation of the inner thigh. Transcranial magnetic stimulation (TMS) and magnetic stimulation of the upper lumbar roots were applied; GFN was stimulated using a surface electrode at the anterior superior iliac spine. RESULTS: CM striated fibers comprised multiple motor end plates. CM needle EMG results were similar to those of the limb muscles in chronic neurogenic disorders. TMS produced clear-cut evoked motor responses from CM. GFN motor conduction time to CM was absent or delayed in patients with inguinal hernia. EMG of CM was abnormal in 40% of patients with premature ejaculation. CONCLUSION: CM is different from other skeletal muscles both morphologically and physiologically. Intersegmental sacrolumbar reflexes are useful for evaluating ejaculatory dysfunction. SIGNIFICANCE: CM is an important muscle for testis thermoregulation and sexual reflexes. Neurophysiological techniques are available for physiological and clinical studies.

Medium-latency reflex response of soleus elicited by peroneal nerve stimulation.

A medium-latency response (MLR) has been recorded from soleus during stance and walking, and has been attributed to stretch-evoked volleys in group II afferents. The present paper describes a MLR in soleus evoked by stimulating the deep peroneal nerve, documents its characteristics and addresses its likely origin. The MLR of soleus was recorded in healthy subjects and hemiplegic patients, following electrical stimulation of the deep peroneal nerve at the fibula at rest, during voluntary dorsiflexion, during plantar flexion, during external restraint to the ankle dorsiflexion movement, during limb cooling, during limb ischaemia and 1 h after the ingestion of tizanidine. The dorsiflexion movement of the foot was measured using an accelerometer. During cooling, ischaemia and after tizanidine, changes in the MLR were compared with changes in the soleus H reflex, Achilles tendon reflex and, during cooling, F waves of abductor hallucis. The MLR was facilitated by voluntary dorsiflexion, was suppressed during plantar flexion, disappeared when ankle movement was prevented, and was enhanced in patients with spastic hemiplegia. Cooling delayed the MLR significantly more than the Achilles tendon reflex and the abductor hallucis F wave. During ischaemia the response was significantly less affected than the Achilles tendon reflex and the soleus H reflex. Tizanidine suppressed the MLR, but not the soleus H and tendon reflexes. The latencies and the experiments using cooling, ischaemia and tizanidine implicate soleus group II afferents in the genesis of this response.

The effects of botulinum toxin A on ephaptic transmission in idiopathic hemifacial spasm.

OBJECTIVE: Lateral spreading and synkinetic responses of blink reflex are a sign of ephaptic transmission in idiopathic hemifacial spasm (HFS). The aim of this study was to evaluate the effect of botulinum toxin A (Btx A) on ephaptic transmission in idiopathic HFS. METHODS: Thirty-three patients with idiopathic HFS were investigated. Btx A was injected only into the affected orbicularis oculi (OC) muscle. Electrophysiological studies were performed before and three weeks after the Btx A injection. RESULTS: After Btx A, the latencies of motor response and blink reflexes elicited from the OC muscle were significantly increased. The lateral spreading was not obtained in the OC muscle, while the orbicularis oris muscle response was not changed. There were no significant differences in the synkinetic responses of blink reflex. During needle EMG examination, positive sharp waves and fibrilation potentials were observed due to chemodenervation only in the OC muscle. CONCLUSION: Btx A affects only the neuromuscular junctions of the injected muscle and has no effect upon ephaptic transmission.

Sacrolumbar intersegmental reflex circuit in men and its relation to the ejaculatory process.

OBJECTIVE: We aimed to investigate electrophysiologically the intersegmental reflex circuit from sacral to lumbar cord segments in normopotent adult men, in patients with spinal cord injury and in patients with premature ejaculation. METHODS: Reflex EMG activity of the cremasteric (CM) and bulbocavernosus (BC) muscles was recorded simultaneously by needle electrodes during electrical stimulation of the upper lumbar and sacral dermatomes, respectively. Thirty-three healthy male volunteers, 16 patients with spinal cord injury (SCI) at the thoracic or cervical levels, and 26 men with premature ejaculation (PME) were included in the study. RESULTS: In controls, upper lumbar dermatomal stimulation (ULS) at the inner side of thigh only elicited a reflex response from the CM muscle and did not produce a regular response from the lower sacral myotomes such as in the BC muscle. However lower sacral dermatomal stimulation (LSS) at the dorsal nerve of penis consistently evoked reflex responses from both CM and BC muscles. These basic electrophysiological features were not different in patients with SCI. LSS did not elicit a reflex response from the CM muscle in about 39% of patients with PME, while the BC reflex was obtained from all patients with PME. CONCLUSIONS: The neurophysiological pattern in BC and CM muscles during sacral or lumbar dermatomal stimulation reflects the sacrolumbar intersegmental reflex linkage that may be related to the ejaculatory process in men. The intersegmental sacrolumbar reflex circuit may be functionally disturbed in some patients with PME. SIGNIFICANCE: Interaction between the reflex activity of sacral to lumbar dermatomes could prove useful in defining electrophysiological mechanisms related to ejaculation in men.

Swallow-induced syncope in 5 patients: Electrophysiologic evaluation during swallowing.

BACKGROUND: We sought to characterize a cohort of participants with swallow-induced syncope (SIS) with clinical and electrophysiologic evaluations. METHODS: Using electrocardiographic monitoring and neurophysiologic methods of swallowing, we evaluated a cohort of 5 patients with SIS, 4 of whom had longitudinal follow-up. RESULTS: We determined electrophysiologically that the duration between the onset of swallow and a bradyarrhythmia or asystole is extremely short (2-3 seconds) in SIS. Most participants with SIS do not have a neurologic or esophageal disorder. SIS can occur with different food types, in sitting or standing position, and has varying frequency in different participants. Permanent pacemaker placement is a curative measure in SIS. CONCLUSIONS: Our findings suggest that SIS is elicited by reflex afferent pathways originating in the oropharynx, rather than an esophageal origin, as previously proposed. Our longitudinally followed cohort with detailed clinical and electrophysiologic characterization should aid the clinician in the diagnosis and treatment of this potentially life-threatening condition.

Guillain-Barré Syndrome and Swallowing Dysfunction.

PURPOSE: Patients with Guillain-Barré syndrome (GBS), especially severe cases that require treatment in intensive care units, often experience swallowing difficulties. However, the oropharyngeal function of patients with GBS not treated in intensive care units is not typically evaluated using neurophysiological techniques. METHODS: Electrophysiological techniques were used to determine dysphagia limit and sequential water swallowing values in an electromyography laboratory. RESULTS: This study assessed 18 patients with GBS who were not treated in the intensive care unit between 4 and 45 days after their hospital admission; 18 healthy volunteers were used as a control group. Of the 18 patients with GBS, 7 exhibited the clinical involvement of either a single cranial nerve or a combination of cranial nerves while 11 did not show any lower cranial nerve involvement. Clinical dysphagia was observed in seven patients and six of these cases involved a lower cranial nerve while five patients without cranial nerve involvement had silent dysphagia according to the dysphagia limit test. In addition, the duration of sequential swallowing was significantly prolonged in all patients with GBS compared with the control subjects. CONCLUSIONS: The present findings demonstrated that neurophysiological techniques are useful and easily applicable for patients with GBS and that there were no complications. Furthermore, cranial nerve involvement in patients with GBS likely increased the incidence of oropharyngeal dysphagia, and subclinical dysphagia may be present in this population as well. Therefore, neurophysiological techniques can be initially used and then repeated during follow-up visits for all types of patients with GBS.

Spontaneous yawning in patients with multiple sclerosis: A polygraphic study.

BACKGROUND: Patients with multiple sclerosis (MS) suffer from the repetitive yawning and sleep problems. Yawning is observed in MS and other central nervous system disorders and yawning and swallowing may be controlled by the network of the brain stem. Therefore it is important to investigate the MS patients with various clinical and radiological locations in order to understand the role of brainstem on the yawning mechanisms. One hour polygraphic recording would be crucial method for this purpose, because it is easy to observe spontaneous yawning (SY) and spontaneous swallowing (SS) together with their electrophysiologic counterparts. Previous studies reported that contagious yawn and swallow are temporally related and frequency of swallows was increased within 10s of post yawn period in normal adult subjects. We have re-investigated this phenomenon by studying the SY and SS in polygraphic recording in normal subjects and patients with MS. Then we hypothesized that SY is expected to be increased in MS patients. METHODS: 49 patients with MS and 19 control subjects were recruited in this study. We used a twelve-channel electroencephalography (EEG) device. Five channels were for electromyography (EMG) recording. We also used one channel for laryngeal sensor for vertical movements of the larynx during swallowing. Cardiac rhythm, respiration and sympathetic skin responses were synchronously recorded during swallowing. We evaluated rate of total SY, swallows inside the yawning, before and after 10s of the yawning and yawning unrelated with swallowing. RESULTS: Patients with MS yawned more frequently than healthy controls (p = 0,044). It was obvious that the yawning unrelated with spontaneous swallow was also significantly increased compared to normal controls (p = 0,047), whereas swallowing inside the yawn or before and after 10s of yawning were not significantly different in both groups. Among 49 MS patients, 16 (32.6%) had brainstem involvement. Yawning was observed in only 6 (37.5%) of them. CONCLUSION: Yawning is significantly increased in MS patients compared to normal controls by using the polygraphic method. There is no direct relation of the brainstem and the origin of yawning in MS patients according to clinical picture and MRI findings. However safe swallows during yawning could suggest that there is still need to some brain stem mechanism and/or oropharyngeal reflexes. Difficulties must be emphasized to detect anatomic localization in MS because of relapsing pattern of disease.

Electrophysiologic identification and evaluation of stylohyoid and posterior digastricus muscle complex.

PURPOSE: To identify the function of stylohyoid and posterior digastricus (STH-PD) muscle complex by the EMG techniques. METHODS: Unaffected sides of the faces of 30 patients with facial paralysis or hemifacial spasm were investigated. A concentric needle electrode was inserted to the STH-PD muscle complex and another concentric needle electrode was inserted to the orbicularis oris (OO) muscle. Simultaneous recording were obtained from two muscles using electrical stimulation (ES) (in 25 cases) and magnetic coil stimulation (MS) (in 15 cases); and both in 10 cases. Afterwards, the function of STH-PD was studied such as whistling, lip pursing, swallowing, jaw opening and closing. RESULTS: (1) The motor latency of compound muscle action potential (CMAP) of the STH-PD muscle was shorter than that of OO. (2) When the facial nerve was stimulated more distally than the stylomastoid foramen, the CMAP elicited from the STH-PD muscle complex immediately disappeared. (3) Ipsilateral MS was able to elicit the motor evoked potential (MEP) from STH-PD either at intracranially (half of cases) or at the extracranially. While OO muscle was always stimulated intracranially by MS. (4) The STH-PD muscle complex could not be basically recruited by the mimicry except lip pursing. The main recruitment were provided by swallowing and jaw opening. Cortical MS were facilitated during swallowing (5) Late reflex responses appeared in the STH-PD muscle complex during infraorbital-trigeminal and facial nerve ES. CONCLUSION: The STH-PD muscle complex is identified electrophysiologically. Although it is innervated by the facial nerve, its functions are mainly related with jaw opening and oropharyngeal swallowing. However, it is activated by the lip pursing.

Spontaneous Swallowing during All-Night Sleep in Patients with Parkinson Disease in Comparison with Healthy Control Subjects.

STUDY OBJECTIVES: Spontaneous saliva swallows (SS) appear especially during sleep. The rate of SS was rarely investigated in all-night sleep in patients with Parkinson disease (PD). Dysphagia is a frequent symptom in PD, but the rate of SS was never studied with an all-night sleep electroencephalogram (EEG). METHODS: A total of 21 patients with PD and 18 age-matched healthy controls were included in the study. Frequencies of SS and coughing were studied in all-night sleep recordings of patients with PD and controls. During all-night sleep, video-EEG 12-channel recording was used including the electromyography (EMG) of the swallowing muscles, nasal airflow, and recording of vertical laryngeal movement using a pair of EEG electrodes over the thyroid cartilage. RESULTS: The total number of SS was increased while the mean duration of sleep was decreased in PD when compared to controls. Sialorrhea and clinical dysphagia, assessed by proper questionnaires, had no effect in any patient group. The new finding was the so-called salvo type of consecutive SS in one set of swallowing. The amount of coughing was significantly increased just after the salvo SS. CONCLUSIONS: In PD, the rate of SS was not sufficient to demonstrate the swallowing disorder, such as oropharyngeal dysphagia, but the salvo type of SS was quite frequent. This is a novel finding and may contribute to the understanding of swallowing problems in patients with dysphagic or nondysphagic PD.

Peripheral component of laryngeal and pharyngeal motor evoked potentials.

In this study, the responses of thyroarytenoid (TA) and cricopharyngeus (CP) muscles were simultaneously recorded to peripheral magnetic stimulation of the vagus nerve. Recordings were performed in 13 subjects by means of concentric needle EMG electrodes inserted in the TA and CP. Magnetic shocks were delivered to the vagus nerve with a round coil placed occipitally, while EMG was silent in the TA. In all subjects, clear-cut responses were obtained simultaneously in both muscles. In TA compared to CP, the maximum amplitude of the responses were higher, whereas the onset latency was shorter. Our results revealed that simultaneous recordings of TA and CP motor responses to occipital magnetic stimulation enabled a reliable evaluation of their peripheral innervation by the vagus nerve.

Dysphagia in Alzheimer's disease.

OBJECTIVE: To investigate electrophysiological parameters of swallowing in all stages of Alzheimer's disease. METHODS: Forty Alzheimer's disease patients, 20 age-matched normal controls and 20 young normal controls were included. Dysphagia limit (DL) and sequential water swallowing (SWS) tests were performed. Cardiac rhythm, respiration and sympathetic skin responses were concomitantly recorded. RESULTS: Dysphagia was found in 30/40 (75%) of Alzheimer's disease patients. Mean volume at the DL test was significantly reduced (16.5±1.0mL) in the Alzheimer's disease group. Swallowing and apnea times in the SWS test were significantly prolonged in elderly controls, but even longer in Alzheimer's disease patients. CONCLUSIONS: Alzheimer's disease patients had electrophysiological features of dysphagia, even in the early period of disease. The cortical involvement and severity of cognitive disorder can increase swallowing problems, but subclinical signs of dysphagia may be observed even in patients with mild or moderate Alzheimer's disease.

Corticonuclear innervation to facial muscles in normal controls and in patients with central facial paresis.

Recently it has been proposed that corticobulbar innervation of the lower facial muscles is bilateral, that is from both right and left sides of the motor cortex. The objectives of this study were, i) to evaluate the corticonuclear descending fibers to the perioral muscles and, ii) to determine how central facial palsy (CFP) occurs and often recovers rapidly following a stroke. Eighteen healthy volunteers and 28 patients with a previous history of a stroke and CFP (mean ages: 51 and 61 years) were investigated by TMS (transcranial magnetic stimulation) with a figure of eight coil. Intracranial facial nerve and cortical motor evoked potentials (MEPs) were recorded from the perioral muscles. The periorbital MEPs were also studied. The absence of MEPs in both perioral muscles with TMS of the affected hemisphere was the most obvious abnormality. Also, central conduction time was significantly prolonged in the remaining patients. The mean amplitude of the affected hemisphere MEPs was diminished. The amplitudes of the unaffected hemisphere MEPs recorded from the intact side were enhanced especially in the first week following the stroke. During TMS, only the blink reflexes were elicited from the periorbital muscles due to stimulus spreading to trigeminal afferent nerve fibers. It is concluded that perioral muscles are innervated by the corticobulbar tract bilaterally. CFP caused by a stroke is generally incomplete and mild because of the ipsilateral cortical and multiple innervations out of the infarction area, and recovers fast through cortical reorganisation.

Cutaneous silent periods of the vastus medialis evoked by the stimulation of lateral femoral cutaneous nerve.

OBJECTIVE: Cutaneous silent period (CSP), which is a spinal reflex mediated by A-delta cutaneous afferents, is transient suppression of the electromyographic activity. In this study, our aim is to investigate CSPs of vastus medialis muscle (vm-CSP) evoked by the stimulation of the lateral femoral cutaneous nerve (LFCN) in healthy controls and in patients with meralgia paresthetica (MP). METHODS: Twenty-one patients with MP (17 unilateral, 4 bilateral) and 27 healthy controls were included. Nerve conduction studies of LFCN and vm-CSP were analyzed in all subjects. A stimulus train consisting of five electrical shocks was applied to the skin at the anterolateral side of the thigh for recording of the vm-CSP. RESULTS: Nerve conduction abnormalities of LFCN were observed in all patients with MP. Mean duration of vm-CSP was 69.7+/-9.2ms, and mean onset latency was 44.7+/-6.9 in healthy controls. Onset latency of vm-CSP was significantly prolonged and the duration of vm-CSP was significantly shortened in patients with MP. Vm-CSP abnormalities were observed in 20/25 extremities with MP. CONCLUSIONS: Dysfunction of A-delta afferents may cause these findings in patients with MP. Additionally, spinal modulation of pain may also play a role in the explanation of our findings. SIGNIFICANCE: The present study demonstrates the CSP alterations in the patients with entrapment neuropathy of a cutaneous nerve.