Trigemino-autonomic headache related to Gasperini syndrome

Gasperini syndrome is a rare phenomenon, resulting from small ischemic or hemorrhagic lesions of the mediolateral tegmental pons; the core symptoms are caused by the involvement of the VIth and VIIth nerve nuclei or the intrapontine segments of these nerves [5]. The most common cause is the occlusion of the AICA. A recent review of the literature found only a few reports of this syndrome with a total of 13 patients including Gasperini’s original case [6]. A further case was caused by pontine demyelination due to multiple sclerosis [7]. There may have been other cases in whom similar symptoms were not ascribed to Gasperini’s name [8].

Beside the symptoms mentioned above, Gasperini’s original report also described a contralateral hemisensory loss, caused by damage to the spinothalamic tract. This was seen in 11 of the 13 cases, making it the most common accompanying symptom. In some cases the trigeminothalamic tract was also involved, causing sensory disturbance on the contralateral half of the face. None of these were present in our patient. Ipsilateral facial sensory disturbance, suggesting the involvement of the spinal trigeminal tract or nucleus and hearing loss were also quite common (8/13 cases)—both were also part of our patient’s symptoms. The ipsilateral headache involving the V/1 territory, one of the initial symptoms in our patient, had not been described by previous authors. The complaint of vertigo is also unusual. Taken together, our patient’s symptoms indicate the involvement of nerves VI, VII and VIII (nuclear or intrapontine fibers), the trigeminal spinal tract or spinal tract nucleus, cochlear and vestibular nuclei or nerve, and middle cerebellar peduncle. The fact that the nerve VI palsy was not accompanied by double vision is probably due to the mild degree of the weakness and to the horizontal nystagmus which, through the consequent oscillopsia, may have influenced the patient’s ability to discern the misaligned images on attempted right lateral gaze.

With the exception of a single case, all ischemic cases of Gasperini syndrome were caused by the occlusion of the AICA [6]. This artery supplies the lateral inferior pontine tegmentum and middle cerebellar peduncle, vestibulocochlear nerve including the root entry zone, inner ear, and anterior inferior cerebellum [9]. AICA infarcts are uncommon; in a prospective study they accounted for 0.9% of 770 acute strokes [9].

Infarcts in the posterior circulation territory are accompanied by headaches in more than 50% of cases [10] Infarcts in the territory of the posterior inferior and superior cerebellar arteries are very frequently associated with headache which is one of the prominent symptoms [11].

On the other hand, AICA infarcts rarely cause headache: in a study describing 15 cases of AICA infarction not a single patient with headache as one of the symptoms was described [9]. In another study of 15 patients with multiple cerebellar and brainstem infarcts, none of the 5 patients with AICA infarcts reported headache, whereas 5 of the 10 other patients had headache as one of the presenting symptoms [12].

The patient’s head pain changed a lot during the course of the disease. At the onset of symptoms the clinical picture was reminiscent of SUNCT syndrome, albeit with less prominent autonomic accompaniments. First division trigeminal neuralgia with tearing was a less probable option due to the lack of refractory periods between provoked attacks; a refractory period of 2–3 min is very frequent in trigeminal neuralgia, while the great majority of SUNCT patients in the case series of Pareja and Sjaastad [13] did not experience any refractory period after pain triggering. Later the patient’s continuous mild head pain resembled hemicrania continua with superimposed severe attacks reminiscent of paroxysmal hemicrania. The sequential occurrence of different TAC types in the same patient has already been observed in some cases. One patient developed episodic paroxysmal hemicranias that later evolved in hemicrania continua [14]. Recently, Cosentino et al. [15] observed a patient in whom ipsilateral cluster headache, SUNCT and HC developed subsequently. These cases raise the issue of a common pathomechanism of these disorders, which most likely is the central disinhibition of the trigemino-autonomic reflex [16]. While in the primary TACs this disinhibition is probably mediated by hypothalamic activation (as already shown for cluster headache [17] and SUNCT syndrome [18]) through a hypothalamo-trigeminal pathway [19], the present case may have a different explanation.

The headaches caused by posterior circulation infarcts are very probably related to the activation of the trigeminovascular system [20]. In the present case, the involvement of the pontine trigeminal entry zone (which has been implicated in the pathogenesis of trigeminal neuralgia [21] and SUNCT-like headache [22]) may also have led to the attacks of pain and, during severe attacks, to autonomic symptoms by the activation of collaterals of second-order trigeminal neurones to the superior salivatory nucleus. Alternatively, the partial ischemic damage to the spinal trigeminal tract or nucleus (causing ipsilateral facial hypesthesia for pain and temperature) may have led to an aberrant signal transmission to higher-order pain centres.