A 3D kinematic method for evaluating voluntary movements of the cervical spine in humans

The purpose of this study was to assess the reliability of a 3D kinematic method of evaluating movements of the cervical spine. Range of motion (ROM) of the cervical spine was evaluated in 8 control subjects during flexion-extension, rotation and lateral bending movements. The test was repeated on two separate occasions. The ROM test-retest difference ranged from 1.42 degrees for right axial rotation to 9.11 degrees for left axial rotation. The test showed good reliability, with an intraclass correlation coefficient which was higher than 0.74 in extension movement and excellent in flexion, axial rotation and lateral bending. In conclusion, the method proposed for the 3D kinematic analysis of neck movement proved to be useful and non-invasive and to show good-excellent reproducibility. Furthermore the method is easily applicable in clinical practice to evaluate neck function in cervical spine disorders.

Eye movement abnormalities in myotonic dystrophy

We studied saccade and smooth pursuit eye movements in 31 patients suffering from myotonic dystrophy (MD). On the basis of mean value comparisons, saccades were slower and hypometric and smooth pursuit eye movements performed worse in MD patients than in controls. On an individual basis, saccade duration was prolonged in 67.7%, saccades were hypometric in 19.4%, saccade latency was delayed in 9.7%, and the smooth pursuit performance index was decreased in 9.7% of patients. Eye movement abnormalities did not correlate with those detectable by visual, brain-stem auditory and somatosensory evoked potentials. We attempted to classify eye movement abnormalities as myogenic or neurogenic on the basis of differences in combination of eye movement abnormalities and the occurrence of D5/D35 dissociation; the latter consists of a prolonged duration for large (35 degrees) but not for small (5 degrees) saccades. Since D5/D35 dissociation occurred in 26/33 multiple sclerosis patients with increased saccade duration, we considered it to be a neurogenic pattern attributable to a central nervous system (CNS) dysfunction. A prolonged duration without dissociation especially in combination with saccade hypometria, is interpreted as a myogenic pattern, although the lack of dissociation may also occur with CNS impairment in case of a marked increase in saccade duration. Accordingly we classified the oculomotor abnormalities detected as neurogenic in 11 MD patients and as myogenic in another 10, but in some subjects belonging to the second group concomitant CNS impairment is not to be excluded.

Trigeminal evoked potentials in man: a new olfactory stimulation device

The recording of olfactory evoked potentials in healthy humans, using a continuous flow olfactory stimulator, is described. A stimulator pushed inert gas (N2) in a continuous flow through the nose at a rate of 4 l/min. At fixed 30-second intervals, (32 times) the flow was replaced by an equal amount of CO2, a trigeminal stimulant. Each pulse lasted 200 ms. An electronic timing circuit triggered both the stimulator and the recorder. Signal acquisition was performed using an Evoked Potential Recorder (Nicolet Compact Four by Nicolet Biomedical Instruments), triggered by the stimulator. Using this stimulator device reliable olfactory evoked potentials can be recorded in a clinical setting. Since this is a non invasive technique which can be used to test olfactory function whether or not the patient cooperates, it is expected to become widely used, particularly in non collaborating patients and in those suspected of malingering.

Long-term outcome of migraine

Migraine prevalence increases from childhood up until 40 years of age, and thereafter declines. Several hypotheses can be advanced to explain the decrease in migraine with advancing age: (i) favorable effect of preventive treatments; (ii) increased mortality in migraineurs (due to higher vulnerability to other fatal diseases); (iii) cohort effect (increased incidence in young subjects); (iv) spontaneous remission. The first two theses are poorly supported by data in the literature. Although a cohort effect may exist, a spontaneous remission of migraine in middle and old age (at least partially due to the loss of sex hormone changes after the menopause in females) is the more likely hypothesis. In a small subgroup of patients (most of them drug abusers), migraine has a "malignant" course and changes into chronic daily headache. The risk factors for a poor outcome of migraine have been little studied. In a case-control study, we found that a history of head trauma and a long duration of contraceptive intake were risk factors for a bad outcome, whilst a long duration of prophylactic treatments had a protective effect.

Psychiatric comorbidity in chronic daily headache

Clinical evidence suggests that chronic daily headache (CDH) occurs in association with psychopathologies: previous studies have focused particularly on migraine. To evaluate this association, we studied, using the DSM-IIIR criteria, a population of 88 patients (18M, 70F) affected by CDH (mean duration 7.4 +/- 8.7 years). We documented the presence of a psychiatric disorder in 90% of this population. The most frequent diagnosis was a comorbidity of anxiety and mood disorders. The comorbidity of psychiatric disorders and headache has important implications as far as treatment is concerned.

Pain pressure threshold in cluster headache patients

Pain perception threshold (PPT) in the head was assessed with a pressure algometer in 58 cluster headache (CH) patients (52M, 6F; 41 episodic and 17 chronic). Fourteen patients in cluster period were retested in remission. Thresholds were assessed at 10 symmetrical points on each side of the head and at the deltoid. Compared with controls (n = 50), CH patients had lower PPT in the head and in the deltoid. PPT was lower on the symptomatic side than on the non-symptomatic side in patients with episodic CH during a cluster period (p < 0.001) and in patients with chronic CH (p < 0.05). This pattern was more evident during a cluster period than during remission (p < 0.05). A reduced PPT did not correlate with illness duration and pain side. The lowest PPT mean values were found at the anterior and intermediate levels of the temporal muscle on the symptomatic side. These results imply a central mechanism underlying the pathogenesis of CH.

A record card for the study of Neuronal Hyperexcitability Syndrome

Neuronal Hyperexcitability Syndrome (NHS) is a nosographic picture which is difficult to diagnose, due to the lack of specific standard diagnostic criteria. With slightly varying symptoms the syndrome has also been defined as Spasmophilia and Hyperventilation Syndrome. It is difficult to distinguish between NHS and panic attack disorder as there is considerable overlapping of symptomatology. We aimed to propose a standardized card which will be the first step toward a valid diagnosis of this complex neuropsychiatric problem. This card, which will be validated and of which the reliability will be evaluated, is proposed for clinical and research purposes. The card is made up of 6 parts (113 items) covering: personal data, pharmacological treatment, persistent diseases and related therapies, symptomatology trend, factors interfering with calcium-magnesium homeostasis and symptom assessment. The symptom assessment section is essential for the checking of diagnostic criteria and the earlier sections are important for the monitoring of other factors which can cause symptoms able to simulate NHS. There are also two special sections for recording laboratory tests and patients' psychic profiles.

Classification of chronic daily headache by International Headache Society criteria: limits and new proposals

We conducted a retrospective study of 150 patients with chronic daily headache (CDH) to determine how to categorize their headache according to the classification of the International Headache Society (IHS). All patients were first evaluated at Parma and Pavia Headache Centres (from January 1992 to March 1993) and had had headache for at least 15 days a month during the previous 6 months. Four patients were thereafter excluded due to poor reliability. The 146 patients who met our CDH criteria (92 with and 54 without clear-cut migraine attacks) could be classified into four groups: (i) chronic tension-type headache (CTTH)--27 patients; (ii) coexisting migraine plus CTTH--65 patients; (iii) unclassifiable daily headache--27 patients; and (iv) migraine and an unclassifiable interval headache--27 patients. Seventy-two percent of patients with CDH had migraine as the initial form of their headache. We therefore propose to revise the IHS classification for migraine, taking into account its evolution, and add two subcategories, migraine with interparoxysmal headache and chronic migraine.

Comparative study with EMG, pressure algometry and manual palpation in tension-type headache and migraine

According to International Headache Society classification criteria, the presence of pericranial muscle disorder in tension-type headache should be evaluated using one of the following methods: EMG, pressure algometry or manual palpation. The purpose of this study was to compare the results of these three methods in 15 patients with episodic tension-type headache, 29 with chronic tension-type headache and 22 presenting migraine without aura compared to those obtained in healthy individuals. Algometric and EMG recordings at the frontalis muscle during mental arithmetic were more impaired in episodic and chronic tension headache patients than in controls and migraine patients. Chronic tension headache patients were significantly impaired at the trapezius muscle in all three tests compared to controls. Our data indicate that when two or three tests were carried out the diagnostic capacity was significantly improved in comparison to only one test. Moreover, since a different pattern could be seen with pain and without pain, the existence of headache at the time of testing should be taken into consideration.

Neurophysiological studies in chronic paroxysmal hemicrania and hemicrania continua

To explore the possible involvement of the pain control system, pain pressure threshold (PPT), nociceptive flexion reflex (RIII), blink and corneal reflexes have been studied for pain perception assessment in 12 patients with chronic paroxysmal hemicrania (CPH) and 12 patients with hemicrania continua (HC). PPT was found to be reduced in HC and CPH when separately compared to controls. In addition, a significant reduction of subjective pain perception (Tp) which was most marked on the symptomatic side, has been demonstrated after sural nerve stimulation in CPH. The RIII reflex threshold on the symptomatic side was significantly reduced when patients were compared to controls. No major differences between CPH and HC as regards blink reflex latencies were found; nor was any such difference observed when comparing the two headache groups to controls. The corneal reflex thresholds were found significantly reduced bilaterally in CPH, irrespective of whether the treatment was given or not.

Bilateral sympathetic skin response following nociceptive stimulation: study in healthy individuals

Bilateral sympathetic skin response (SSR) was evaluated in 25 normal subjects aged (29 +/- 5 years). The stimulation (an electrical pulse train randomly applied to the sural nerve) was equal to 0.5-1.0-1.5 times the nociceptive flexion reflex (RIII) thresholds. This method allowed us to quantify the pain threshold, since a close relationship between the RIII threshold and subjective pain threshold has been described. Decrease in latency, increase in amplitude and duration were observed when increasing intensity of stimulation was used. The right-side stimulation produced significantly shorter latencies and higher amplitudes than the left one. The asymmetry index showed a trend of larger responses on the left hand and shorter latencies on the right hand in males. Females displayed less left-right asymmetry than males. A positive correlation was recognized between RIII threshold and amplitude and duration of SSR. Test-retest evaluation in 12 individuals revealed good reproducibility of SSR in terms of latency and duration, while amplitudes showed large variability. The accuracy of SSR response concerning latency and duration was better (range 0.88-0.92) when 1.5 RIII threshold was used, showing that painful stimulation should be used to obtain reliable SSR in clinical practice.

Effects of dothiepin on nociceptive flexion reflex and diffuse noxious inhibitory controls in humans

The analgesic activity of dothiepin (an antidepressant interacting with serotonin receptors) was studied (double-blind) in humans. A significant increase in nociceptive flexion reflex threshold and subjective pain threshold was observed after a 14-day dothiepin treatment. The effects of dothiepin on diffuse noxious inhibitory controls were also investigated using the cold-pressor test as conditioning stimuli. After dothiepin a reduced inhibition of nociceptive flexion reflex during the cold-pressor test and a significant facilitation immediately after the cold-pressor test were observed, while the subjective pain perception was normally inhibited. Our data suggest a serotonergic modulation of diffuse noxious inhibitory controls in humans.

The trigemino-pupillary response in cluster headache

Central impairment of the integrative neural systems controlling vegetative function and pain perception has been demonstrated in cluster headache (CH). Recently, we described the human pupillary response (trigeminal reflex) to quantified (painless and painful) corneal stimulation with a combined neurophysiological and pharmacological technique. In this study, the trigeminal reflex was evaluated in 26 subjects with episodic cluster headache. During the active phase of the disease, on the side of the pain we observed reduced mydriasis to electrical stimuli with an intensity equal to the corneal reflex threshold, and on both sides to stimuli with intensity that equalled the pain threshold. No difference was found when amplitude of the miotic phase was compared in the different groups. These suggest disordered pupillary activation in response to pain, probably sympathetic in origin, which is bilateral, detectable also during the remission phase and which cannot be explained simply by the antidromic release of pain-related peptides.

A computerized record chart for the study of chronic daily headache

A comprehensive record chart for the study of chronic daily headache (CDH) is presented. The record chart contains 11 parts (232 items) concerning: sociodemographic data, physiological history, female reproductive life history, family history, pathological history, drug abuse, headache history, headache clinical features, prophylactic therapy, instrumental investigations, and physical and neurological examination. Furthermore, three attached special charts are illustrated which concern, respectively, the cervical spine examination, oromandibular function examination and the assessment of analgesic use.

An epidemiological approach to the nosography of chronic daily headache

Chronic daily headache (CDH), a heterogeneous group of headaches, includes different forms that occur daily, or almost daily, over a prolonged period of time. The nosography of this group is still a matter of debate, and in the most recent classification of the IHS (1988) only a few types of CDH are included: chronic tension-type headache, coexisting migraine. This study is an epidemiological approach to identifying the clinical features of CDH and the possible factors involved in changing episodic headache in CDH. Ninety CDH outpatients were investigated using a computerized record chart. The main observed forms were: (a) chronic tension-type headache--migraine with interparoxysmal headache, an evolved form of migraine in which a constant low severity headache develops between attacks; (b) transformed migraine, an evolved form of migraine with progressive worsening of the disease which reaches the level of continuous pain with the disappearance of typical migraine attacks. Interval headaches in migraine with interparoxysmal headache partly fulfil the IHS criteria for chronic tension-type headache. Analgesic drug abuse plays a prominent role in inducing CDH and in determining its clinical features.

Changes in motoneuron excitability of masseter muscle following exteroceptive stimuli in Parkinson's disease

Changes in motoneuron activity of masseter muscle to exteroceptive stimuli were evaluated in parkinsonian patients. Two different electrophysiological procedures were applied, consisting of exteroceptive suppression of the masseter or excitability curves of the masseteric reflex obtained by using exteroceptive conditioning stimuli. Seven patients not yet treated with dopaminergic or anticholinergic drugs were compared with 10 age-matched normal volunteers. Only the second phase of exteroceptive suppression was examined because correct measurement of the first phase was impossible due to the stimulus artefact. No significant differences were observed in exteroceptive suppression between parkinsonian patients and normals. Early and late inhibitory phases of the excitability curve of the masseteric reflex were obtained in both normals and patients. However, parkinsonians showed less inhibitory change than normals in both early and late phase of the curve. This study confirms that reduced inhibition of the masseteric reflex to exteroceptive stimuli is present in Parkinson's disease. The excitability curve of the masseteric reflex represents a more reliable method than exteroceptive suppression in detecting these abnormalities.

The nociceptive flexion reflex as a tool for exploring pain control systems in headache and other pain syndromes

The authors review the neural pathways mediating nociceptive flexion reflexes, the method for analyzing these reflexes in human beings, and available data on their modulation by supraspinal, opioid as well as serotonergic systems. They present results of studies of the biceps femoris flexion reflex (RIII) in pain syndromes and various types of headache. Nociceptive flexor reflexes appear to be interesting for studying the pathophysiology of head pain mechanisms and possibly for evaluating analgesic treatment.

The trigemino-pupillary reflex: a model of sensory-vegetative integration

Trigeminal stimulation can induce pupillary changes. In vivo and in vitro studies have demonstrated that electrical impulses applied at the trigeminal level can provoke a miotic response, whose nature has been ascribed to the anti-dromic release of neuropeptides (substance P in particular). In order to better define the pupil response to trigeminal stimulation, we investigated the human pupil response to quantified (painless and painful) corneal stimuli by means of a combined (neurophysiological and pharmacological) technique. The response to corneal stimulation was bilateral, direct and consensual. It had a biphasic progression with an initial mydriasis (which directly correlated with the stimulus intensity), followed by a miotic phase. The mydriatic phase disappeared after thymoxamine application, while homatropine pre-treatment prevented occurrence of the miotic phase. The data obtained indicate that the pupillary response to corneal stimulation (trigemino-pupillary reflex) is a multisynaptic reflex with an afferent branch involving the trigeminal system, and an afferent branch involving both the sympathetic and the parasympathetic system. Other pathways, such as the SP-mediated release of acetylcholine, cannot be excluded. Thus the reflex appears to be a potentially useful tool for investigating pain/vegetative interactions in various clinical conditions. In turn, the description of its changes in pathologies characterized by a sympathetic/parasympathetic deficit or by a SP-ergic imbalance will allow us to better describe its inner mechanisms.

Electrophysiological study on jaw-opening reflex recorded from digastric muscle in Parkinson's disease and primary cranial dystonias

We investigated digastric reflex excitability in normals and in patients with extrapyramidal disorders such as primary cranial dystonias and Parkinson's disease. Relationships between exteroceptive suppression of masseter muscle and digastric reflex were also investigated in some cases. Digastric reflex hyperexcitability was observed in dystonic patients when compared to normals and parkinsonian patients. Furthermore, some patients with cranial dystonia presented absence of exteroceptive suppression reflex in masseter muscle with enlarged digastric response. These results indicate hyperexcitability of the digastric reflex and abnormal agonist-antagonist muscle co-contraction in chewing reflexes of patients with cranial dystonias. This shows that digastric reflex is an important electrophysiological investigation to explore the physiopathological mechanisms of primary cranial dystonias.

Electrically elicited short and long-latency responses of intrinsic hand muscles in hereditary ataxias. Effects of isometric and ballistic isotonic voluntary contractions

Short- and long-latency responses (HR and LLR) from thenar muscles were studied in patients with Friedreich's ataxia and pure cerebellar ataxia with later onset by applying electrical stimuli on the median nerve at the wrist. HR and LLR were examined during two different voluntary activities of the opponens pollicis muscle: isometric ("hold") and isotonic ballistic ("move") conditions. A preliminary conventional study of motor and sensory conduction of the median nerve was also carried out. Patients with Friedreich's ataxia had reduced or absent HR and LLR. Furthermore, those who preserved both responses had prolonged HR-LLR interpeak latency. All patients with Friedreich's ataxia also showed peripheral nerve conduction abnormalities, mainly in sensory fibers. These data can be accounted for by the widespread degeneration of many neural structures in this disorder. No abnormalities in HR were observed in pure cerebellar ataxia with later onset, whereas LLR was grossly enlarged in most patients, notably during "move" condition. Since cerebellar structures (especially the cerebellar cortex) are the only ones involved in this disorder, the cerebellum may play a role in modulating LLR. In particular, this effect could be more evident in isotonic ballistic movements.

Accompanying symptoms of cluster attacks: their relevance to the diagnostic criteria

Two-hundred-and-fifty-one consecutive cluster headache (CH) patients referred to the Pavia and Parma Headache Centers were evaluated in order to verify the presence and recurrence of one or more autonomic symptoms. Data obtained show that in 2.8% of patients cluster attacks were not accompanied by localized autonomic symptoms, thus confirming the report of Ekbom. We observed a high prevalence of photophobia, nausea and vomiting. The IHS diagnostic criteria for CH may need to be modified. The high frequency of "general" autonomic symptoms seems to suggest a component of "central" drive in the physiopathology of cluster headache.