Myasthenia gravis associated with tonic pupil

A 41 year-old female patient with acquired autoimmune myasthenia gravis (MG, IIa type) and tonic pupil (Adie's pupil) of the right side was reported. Adie's pupil was pointed out at the same time of the clinical diagnosis of MG in September, 1988. She had the solitary thymoma identified by pneumo-mediastinograph and mediastinal CT scan. Results of the positive anti-nicotinic AChR antibody titer, the positive edrophonium test and the electrophysiological examination gave unambiguous evidences of acquired autoimmune MG with thymoma. Instillations to the eyes of cocaine, pilocarpine and epinephrine, and the pupillary response to the intravenous injection of edrophonium revealed the postganglionic abnormality mainly in the parasympathetic system. There were no other overt symptoms due to dysautonomia. She refused thymectomy. Her myasthenic and pupillary signs became gradually improving without any immunosuppressive medications. It is concluded that two diseases of the patient may be probably caused by multiple organ- or tissue-specific autoantibodies, in addition to pathogenetic significance of Adie's pupil.     

Interaction of tonic labyrinth and neck reflexes in man

Interaction of tonic labyrinth and neck reflexes was studied in 3 healthy volunteers by analyzing changes in Soleus H-Reflex (SHR) area in relation to both lateral tiltings and neck rotations. By using a Kermath chair each subject was tilted laterally from the vertical to the left and to the right up 15° in steps of 5° and at the same time the longitudinal body axis, keeping the head fixed, was rotated to the right and to the left up to 15° in steps of 5°. All combinations of lateral tiltings and neck rotations were tested. Each test position was followed by a return to 0° for both rotation and tilting (control position). Twelve H-reflexes of right soleus muscle were recorded in each test and control position and the changes in RSHR area were expressed as percentage variations from the mean value absorved in the pretest and post-test control position. Out data indicate that in man, as in animals, labyrinth and neck reflexes act in the opposite direction, and that in the static condition their contribution to postural stabilization is equal.

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Sommario Al fine di studiare nell'uomo le interazioni reciproche dei riflessi tonici labirintici e tonici del collo abbiamo analizzato le variazioni dell'area del riflesso H del muscolo soleo indotte da diverse combinazioni di rotazione del collo ed inclinazioni laterali dell'asse corporeo su 3 soggetti volontari sani. Dalla posizione verticale venivano inclinati lateralmente verso destra e verso sinistra di 5° in 5° fino ad un massimo di 15° e contemporaneamente veniva ruotato l'asse corporeo, tenendo il capo fisso, di 5° in 5° fino ad un massimo di 15°. In ciascun soggetto venivano studiate tutte le possibili combinazioni di inclinazioni e rotazioni. Ogni posizione test veniva fatta seguire da una posizione di controllo a 0° (capo in posizione primaria ed asse corporeo verticale). In ciascuna posizione test e di controllo venivano registrati 12 riflessi H e di ciascuno si misurava l'area. I valori ottenuti nelle diverse posizioni test venivano espressi come percentuale della media dei valori osservati nella corrispondente posizione di controllo precedente e successiva. I risultati così ottenuti indicano che nell'uomo, come nell'animale, i riflessi tonici labirintici e tonici del collo agiscono esercitando sul tono estensorio dell'arto inferiore azioni opposte e di entità sovrapponibile.

     

A case of ocular neuromyotonia with tonic pupil.

A 48-year old woman with hypertension experienced painful oculomotor nerve palsy. After surgery for a giant aneurysm of the internal carotid artery in the cavernous sinus, phasic constrictions of the pupil developed. Two years later, this phenomenon disappeared and was replaced by intermittent involuntary cyclic spasms elevating the ptosed lid. These cyclic lid movements were not elicited with any eye movement or by increased accommodation. The pupil now manifested the pharmacologic features of a tonic pupil. The explanation for this unique case of ocular neuromyotonia is based on a misdirection phenomenon, possibly caused by ephaptic transmission.     

A case of bilateral tonic pupil (Holmes-Adie syndrome)

The authors present a case of bilateral tonic pupil and discuss clinical and physiopathological aspects of this syndrome. They discuss some elements necessary for the understanding of the etiopathogenesis of the disease.     

Adie's tonic pupil as a manifestation of Sjögren's syndrome

We here report two cases of Adie's tonic pupil, associated with clinical sensory polyneuropathy and Sjögren's syndrome, in one of whom it actually heralded the onset of the syndrome. Electrophysiology studies indicated absent H reflexes but normal peripheral nerve conductions, thus suggesting an involvement of the dorsal roots or spinal ganglion that would be in line with previously published reports of dorsal ganglionitis as the primary neuropathological lesion in Sjögren's syndrome. We suggest that all cases of tonic pupils should be screened for polyneuropathy and Sjögren's syndrome.     

Adie''s tonic pupil as a manifestation of Sj?gren''s syndrome

We here report two cases of Adie's tonic pupil, associated with clinical sensory polyneuropathy and Sjögren's syndrome, in one of whom it actually heralded the onset of the syndrome. Electrophysiology studies indicated absent H reflexes but normal peripheral nerve conductions, thus suggesting an involvement of the dorsal roots or spinal ganglion that would be in line with previously published reports of dorsal ganglionitis as the primary neuropathological lesion in Sjögren's syndrome. We suggest that all cases of tonic pupils should be screened for polyneuropathy and Sjögren's syndrome.

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Sommario Descriviamo qui due casi di pupilla tonica associati con una polineuropatia sensitiva clinica e sindrome di Sjögren. Gli studi elettrofisiologici documentavano un'assenza dei riflessi H con conduzioni periferiche conservate, e suggerivano una lesione a livello delle radici dorsali o del ganglio spinale, come riscontrato nei rari studi neuropatologici dimonstranti ganglionite dorsale in corso di sindrome di Sjögren.Suggeriamo che tutti i casi di pupilla tonica isolata siano esaminati per polineuropatia e sindrome di Sjögren.

     

Adductor T reflex abnormalities in patients with decreased patellar reflexes

The adductor reflex (AR) is a tendon reflex that has various features that differ from other tendon reflexes. This reflex was tested in different disorders presenting with diminished patellar reflexes such as diabetic lumbosacral radiculoplexus neuropathy (DLRPN), L2–L4 radiculopathy, and distal symmetric diabetic neuropathy (diabetic PNP). The AR and crossed‐AR (elicited by tapping the contralateral patellar tendon) were recorded using concentric needle electrodes. Additionally, the patellar T reflex (vm‐TR) and vastus medialis H reflex (vm‐HR) were recorded using surface electrodes. AR was recorded in only one out of eight patients with DLRPN, but it was recorded in 21 out of 22 patients with L2–L4 radiculopathy (95.5%). Of these reflexes, only AR showed prolonged latency in the L2–L4 radiculopathy group. The latencies of AR, vm‐TR, and vm‐HR were prolonged in patients with diabetic PNP. We conclude that AR can be useful in the differential diagnosis of some lower motor neuron disorders that present with patellar reflex disturbance. Muscle Nerve 40: 264–270, 2009     

Effect of baclofen upon monosynaptic and tonic vibration reflexes in patients with spasticity

Measurements of monosynaptic reflex activity were made in 10 patients with spasticity before and during treatment with baclofen. There was evidence of both central sensory facilitation and increased fusimotor drive in untreated patients compared with controls. During treatment with baclofen, the central facilitation was reduced but there was no evidence of a reduction in fusimotor drive. The torque developed by vibration of the belly of the biceps and triceps muscles was not significantly different in 14 patients with spasticity compared with controls, and was not altered by treatment with baclofen despite clinical improvement in 12 of the patients. It is suggested that baclofen reduces the excitability of the monosynaptic reflex arc from dynamic spindles but does not affect the mechanisms responsible for the tonic vibration reflex.     

Phasic and tonic reflexes evoked in human antagonistic wrist muscles by tendon vibration

The electromyographic reflex responses of the voluntarily contracting wrist flexor and extensor muscles to periods of vibration-evoked enhanced, Ia-dominated afferent discharge from flexor carpi radialis (FCR) were studied in normal human subjects. Three main response phases were characterised, namely, (i) phasic 'on' responses elicited at the commencement of stimulation, (ii) tonic response levels occurring during prolonged stimulation and (iii) phasic 'off' responses elicited at the termination of stimulation. The phasic 'on' reflex responses of FCR and extensor carpi radialis (ECR) comprised, respectively, a peak of autogenetic excitation of group mean latency 18.8 ms and a trough of reciprocal inhibition of group mean latency 38.0 ms. Prolonged (2 s) trains of FCR (agonist) vibration evoked a phase of tonic reflex excitation in FCR whose mean level was significantly increased, by 20%, above pre-stimulus activity and which did not change over the 0.5-2.0 s vibration period. Progressive reduction of the duration (from 2000 ms to 100 ms) of vibration trains demonstrated that phasic disfacilitatory 'off' troughs regularly occurred, with a consistent latency (mean 24.2 ms), on withdrawal of each period of enhanced Ia-input. This indicates that the responsible excitatory reflex mechanism was operational for the entire duration of each of the vibration periods tested. The extra latency (on average 5.4 ms) of phasic 'off' relative to 'on' responses may be attributed to factors (e.g. 5-10 ms duration of unitary muscle action potentials and afterdischarge in reflex pathways) which inevitably delay the appearance of overt disfacilitatory reductions in EMG rather than the involvement of different reflex pathways. Thus, short-latency, possibly monosynaptic, reflex excitation contributed throughout the entire tonic excitatory response. Sustained FCR (antagonist) vibration produced a significant tonic reciprocal inhibitory reflex depression, by 7% pre-stimulus EMG, of ECR activity which remained steady during the 0.5-2.0 s vibration period. The absence of well-defined phasic disinhibitory 'off' responses in ECR suggests that the contribution of oligosynaptic reflex inhibitory mechanisms to the tonic suppression of activity occurring during continuing vibration is relatively small.