Abstract
According to the classification of the International Headache Society, cluster headache is a severe unilateral orbital, supraorbital or temporal pain lasting 15–180 min if untreated. It is usually associated with symptoms of autonomic nervous system dysfunction, including conjunctival afflux, dacryorrhoea, and ipsilateral sensation of nasal obstruction (1). Recently, autonomic crisis occurring alone and without headache has been reported under the classification of ‘cluster headache sine headache’ (2, 3).
We present a man with a history of typical cluster headache, who developed daily morning hemifacial spasm without headache. After several episodes of daily headache, he experienced daily occurrence of acephalgic hemifacial spasm every morning, lasting 120 min. We consider the pathophysiology of this daily morning hemifacial spasm to be similar to that of cluster headache.
Case report
A 34-year-old man was first admitted to our hospital in April 2000 after developing severe left retro-orbital pain. The pain was recurrent, throbbing and unilateral. It was localized to the periorbital area and accompanied by autonomic symptoms such as conjunctival afflux, dacryorrhoea and sensation of nasal obstruction. Episodes occurred every morning, lasting from 60 to 120 min. The patient was diagnosed as having cluster headache. The pain resolved immediately after inhalation of high concentrations of oxygen (100%, 8 l/min) by mask. Subcutaneous injection of sumatriptan and oral zolmitriptan were also effective. Daily attacks persisted for 1 month before resolving. A similar series of cluster headaches recurred in March 2001 and in March 2002, but did not arise from April 2002 to June 2003, when the patient was readmitted because of hemifacial spasm. Five days before the second admission, the patient experienced morning occurrence of left hemifacial spasm involving the orbicularis oculi muscle, of a strength that made opening the eye impossible. Spasm occurred every morning until admission, but usually resolved spontaneously within 2 h. Headache did not accompany these episodes. The patient reported no medical history of note other than cluster headache and no one in his family had experienced cluster headache or migraine.
At the time of admission, body temperature was 36.6°C and blood pressure was 120/80 mmHg. No physical or neurological abnormalities were identified. Blood and urine analyses were unremarkable. Magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) of the brain did not show any cerebral, orbital or vascular abnormalities. Besides the usual MRI/MRA, a three-dimensional time-of-flight sequence with multiple overlapping thin slab acquisition in an axial orientation was used to generate the MRA images. There were no vascular loop compression of the facial nerve, offenders, or anomalies in the vertebro-basilar system.
During admission, hemifacial spasm occurred every morning. Episodes resolved spontaneously within 2 h or after 40-min inhalation of high concentrations of oxygen. Subcutaneous injection of sumatriptan was also dramatically effective, with spasm ceasing within 10 min. Oxygen inhalation therapy and subcutaneous injection of sumatriptan were therefore administered every morning. Daily morning hemifacial spasm continued for 1 month, ceasing in July 2003. Symptoms returned in June 2004, and this time were often accompanied by cluster headache. The hemifacial spasm tended to become more severe with increasing intensity of headache. Both hemifacial spasm and headache improved dramatically on oral administration of zolmitriptan.
Discussion
In the present case, hemifacial spasm exhibited the following clinical features: (i) daily morning attacks; (ii) spontaneous resolution within 2 h; (iii) dramatic response to oxygen inhalation therapy and subcutaneous injection of sumatriptan; and (iv) a series of daily attacks lastingd 1 month.
It is now widely accepted that hemifacial spasm arises primarily from compression of the facial nerve at the root exit zone of the pons, usually by an adjacent artery (4). However, the present case involved a young man with no risk factors for arteriosclerosis, and no vascular anomalies of the vertebral or basilar arteries were detected on MRI and MRA.
We believe that hemifacial spasm in the present case occurred by the same mechanism as cluster headache, because the above-mentioned clinical features of hemifacial spasm occurred in a pattern similar to that of cluster headache and because the recurrence of hemifacial spasm in June 2003 was actually accompanied by cluster headache. Cluster headache is often accompanied by symptoms related to stimulation of the parasympathetic nervous system, such as conjunctival afflux, dacryorrhoea and sensation of nasal obstruction. However, the exact pathophysiology of this condition has not been established. It has been hypothesized that cluster headache represents one epiphenomenon of ‘trigeminal autonomic cephalgias’ (TACs) (5), a combination of short-lasting headache and autonomic features, a classification that includes cluster headache, chronic paroxysmal hemicrania, episodic paroxysmal hemicrania, short-lasting unilateral neuralgiform headache with conjunctival injection and tearing (SUNCT syndrome) and hemicrania continua (6). These conditions are characterized by a nexus of activation between trigeminal afferents and cranial parasympathetic efferents, i.e. trigeminal-autonomic activation. Anatomical and functional connections exist between the trigeminal nerve and facial motoneurons (7, 8). We therefore considered that facial motoneurons were stimulated by the activation of the trigeminal nerves themselves as well as by trigeminal-autonomic activation, and that hemifacial spasm in the present case was induced by the former. The previous literature contains no similar cases, apart from one case of TAC-like headache accompanied by blepharospasm [9].
A unique feature of the present case is that hemifacial spasm unaccompanied by headache occurred in the first episode. Facial hemispasm without headache can be explained by the difference in activation thresholds for trigeminal afferents and for facial motoneurons, and would appear to result from the activation of the trigemino-facial motoneuron pathway alone. A similar phenomenon has been termed ‘cluster headache sine headache’ (2, 3), in which only parasympathetic symptoms (recurrent attacks of unilateral facial autonomic symptoms) were present.
In conclusion, hemifacial spasm in a patient with a history of cluster headache should be considered as a subtype of the cluster headache syndrome.