Facial Nerves Was Found in This Patient with a Unilateral Pure Motor Stroke Due to Ischaemia in the Pons

73272ournal ofNeurology, Neurosurgery, and Psychiatry 1995;58:732-734

SHORT REPORT J Neurol Neurosurg Psychiatry: first published as 10.1136/jnnp.58.6.732 on 1 June 1995. Downloaded from

Volitional type of facial palsy associated with pontine ischaemia

Rudolf T6pper, Christoph Kosinski, Michael Mull

Abstract nounced during voluntary contraction A dissociation between voluntary and whereas emotionally triggered contractions emotional facial innervation is described are preserved or at times even exaggerated on in a patient with a pure motor stroke due the paretic side.' In the emotional type of to a unilateral ischaemic pontine infarc- facial palsy the opposite phenomenon can be tion. Voluntary facial innervation of the seen: whereas voluntary triggered contrac- contralateral orbicularis oris muscle was tions are normal, there is facial impairment affected whereas emotionally induced during emotionally triggered movements. innervation of the same muscle was Automatic voluntary dissociation is not spared. This report provides evidence restricted to muscles supplied by the facial that fibres conveying voluntary and emo- nerve: in the bilateral anterior opercular syn- tional commands are still separated in drome automatic voluntary dissociation is Department of the pons. Whereas corticobulbar tracts also seen in masticatory muscles supplied by Neurology carry the information for voluntary facial the trigeminal nerve, in the tongue, and in R Topper innervation, efferents from the amygdala muscles involved in swallowing.2 Whereas the C Kosinski and the lateral hypothalamus are candi- volitional type of facial palsy is thought to be Department of Neuroradiology, dates for the somatomotor aspects of caused by a lesion in the motor cortex or in Technical University emotions. the corticobulbar pathways, lesions in the ofAachen, Aachen, basal ganglia, the hypothalamus, or the thala- Germany (7 Neurol Neurosurg Psychiatry 1995;58:732-734) M Mull mus can cause an emotional facial palsy.3 The Correspondence to: precise neuroanatomical basis of automatic Dr Rudolf Topper, voluntary dissociation, however, has Department of Neurology, volitional facial ischaemia Pauwelsstrasse 30, 52057 Keywords: paresis; pontine remained obscure. It is not clear at what level Aachen, Germany. above the facial nucleus fibres conveying voli-

Received 15 December 1994 In patients with the volitional type of central tional and emotional information converge. http://jnnp.bmj.com/ Accepted 8 February 1995 facial palsy facial involvement is most pro- We describe a patient who had an ischaemic

Figure 1 Volitional facial paresis when patient was asked to bare his teeth (A). Symmetric movement with emotional responses (laughing) (B). ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~....~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~.~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~.:!. on September 28, 2021 by guest. Protected copyright. Volitional type offacial palsy associated with pontine ischaemia 733

Figure 2 T2 weighted J Neurol Neurosurg Psychiatry: first published as 10.1136/jnnp.58.6.732 on 1 June 1995. Downloaded from MRI (SE 3-0 sf90 ms) in axial (A) and sagittal (B) planes. Hyperintense lesion of the right upper pons is visible consistent with anteromediallanterolateral pontine infarction. Note the typical wedge shaped lesion in the sagittal plane (B) that spares the pontine tegmentum.

-I eral ischaemic pontine infarction with volitional facial paresis was made. stroke in the upper pons; he presented with a volitional type of facial paresis indicating that the pathways subserving volitional and emo- Discussion tional input on to the facial nucleus are still A dissociation of volitional and emotional anatomically separated in the upper pons. facial nerves was found in this patient with a unilateral pure motor stroke due to ischaemia in the pons. This finding may provide new Case report information on the neuroanatomical organisa- A 57 year old man was admitted to the neu- tion of facial innervation. Voluntary motor rology department because of a central pare- impulses from the motor cortex descend sis of his left arm and leg with sudden onset. through the internal capsule and either make His medical history was unremarkable. There direct connections with the facial nucleus was no trauma preceding the episode. On or terminate in the pontine reticular neurological examination the patient was alert formation.45 The pathway by which emo- and oriented. He had a facial paresis with rel- tional commands reach the facial nucleus is ative sparing of the upper portion of the face. not clear in humans. Information from the http://jnnp.bmj.com/ When asked to bare his teeth there was amygdala and the lateral hypothalamus, drooping of the angle of the left side of his which are thought to be involved in the gen- mouth (fig 1A). On involuntary contraction, eration of emotions, reach the brainstem via however, there was symmetric innervation of the medial forebrain bundle and the dorsal the muscles of the mouth (fig 1B). The longitudinal fasciculus.6 Unlike corticobulbar remainder of the cranial nerve examination tracts the amygdala and the lateral hypothala- was was no unremarkable; specifically there mus do not have direct projections to the on September 28, 2021 by guest. Protected copyright. disturbance of oculomotor function. He had a motor nuclei of the facial nerve but send 3/5 paresis of the left arm and leg with axons to the lateral tegmentum where reflexes being more pronounced on the left. intemeurons for the facial nerve are located.7 Babinski's sign was positive on the left, nega- These polysynaptic pathways are considered tive on the right side. Cerebellar and sensory to form an anatomical basis for somatomotor function were normal. components of affective behaviour48 and are A brain CT obtained eight hours after the therefore likely candidates for conveying onset of symptoms showed no brainstem emotional responses to the facial nucleus. lesion. Fourteen days after the event MRI That a lesion of these tracts to the lateral showed a large hyperintense lesion of the tegmentum may cause an emotional facial right upper pons on T2 weighted images (fig paresis has already been postulated by 2A and B). This lesion respected the midline, Wilson.9 The dissociation in our patient can, had contact with the ventral circumference, therefore, be explained by a pyramidal tract and spared the lateral pontine border and the lesion in the upper pons that disrupts the pontine tegmentum. corticobulbar fibres to the facial nucleus Extracranial and transcranial Doppler whereas efferents from the amygdala and the sonography showed no evidence of stenosis or lateral hypothalamus to the lateral tegmental dissection of extracranial or accessible cranial area are spared. Because emotional facial arteries. Transthoracic and transoesophageal responses such as laughter and crying involve echocardiography was also unremarkable. stereotyped bilateral innervation of facial A diagnosis of an anteromedial/anterolat- muscles'0 it can be argued that the efferents 734 Topper, Kosinski, Mull

2 Weller M. Anterior opercular cortex lesions cause dissoci- from the amygdala and the hypothalamus are J Neurol Neurosurg Psychiatry: first published as 10.1136/jnnp.58.6.732 on 1 June 1995. Downloaded from ated lower cranial nerve palsies and anarthria but no organised bilaterally. In our patient one aphasia: Foix-Chavany-Marie syndrome and "automatic postulate that emotional voluntary dissociation" revisited. Neurol 1993;240: could, therefore, 119-208. information reached the facial nucleus via the 3 Hopf HC, Miiller-Forell W, Hopf NJ. Localization of fibres. This hypothesis emotional and volitional facial paresis. Neurology undamaged ipsilateral 1992;42:1918-23. is, however, contradicted by the overwhelm- 4 Brodal A. Neurological anatomy in relation to clinical medi- ing majority of patients with hemispheric cine. 3rd ed. New York: Oxford University Press, 1981:660-3. lesions of descending motor tracts in whom 5 Holstege G, Kuypers HGJM. Propriobulbar fibre connec- there is both a volitional and an emotional tions to the trigeminal, facial, and hypoglossal motor nuclei. I. An anterograde degeneration study in the cat. facial palsy. The voluntary and emotional Brain 1977;100:239-64. type of innervation of the facial nucleus there- 6 Nieuwenhuys R, Voogd J, van Huijzen C. The human central nervous system. New York: Springer, 1988: fore seems to follow a common pattern with 293-364. bilateral projections to the muscles of the 7 Holstege G. Subcortical limbic systems projections. In: Paxinos G, ed. The human nervous system. San Diego: upper two thirds of the face and unilateral Academic Press, 1990:261-86. to the lower third. 8 Crosby EC, Dejonge BR. Experimental and clinical stud- projection ies of the central connections and central relations of the facial nerve. Ann Otol Rhinol Laryngol 1963;72:735-55. We thank Professor Noth and Professor Poeck for critical 9 Wilson SAK. Some problems in neurology. No II: patho- reading of the manuscript. logical laughing and crying. J3ournal of Neurology and Psychopathology 1924;16:299-333. 1 Monrad-Krohn GH. On the dissociation of voluntary and 10 Poeck K. Pathological laughter and crying. In: Vinken PJ, emotional innervation in facial nerve paresis of central Bruyn GW, Klawans HL, eds. Handbook of clinical origin. Brain 1924;47:22-35. neurology. Vol 45. Amsterdam: Elsevier, 1985:219-25. http://jnnp.bmj.com/ on September 28, 2021 by guest. Protected copyright.