Neurology -- Correspondence for Kumral et al., 63 (12) 2429-2432

Correspondence published:

Reply to Lanska: Emre Kumral (21 April 2005)

Strokes in the subinsular territory: Clinical, topographical, and etiological patterns: Douglas J. Lanska (21 April 2005)

Strokes in the subinsular territory: Clinical, topographical, and etiological patterns: Yasuo Iwasaki, Osamu Igarashi, Yasumitsu Ichikawa and Ken Ikeda (1 March 2005)

Reply to Iwasaki et al: Emre Kumral (1 March 2005)

Reply to Lanska 21 April 2005

Emre Kumral,
Ege University, Department of Neurology
Stroke Unit, Bornova, Izmir, 35100, Turkey
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Re: Reply to Lanska

ekumral{at}med.ege.edu.tr Emre Kumral

We thank Dr. Lanska for his interest in our article. In our series, eight patients presented with either faciobrachial or faciobrachiocrural facial paresis. Two (numbers 7 and 11) had volitional facial paresis. Their faces looked symmetric at rest, but facial movements were reduced on the left (no. 7) and the right (no. 11) side when they were asked to voluntarily show their teeth or quickly alternate between widening and pursing lips. Their smiling and natural laughing were symmetric.
There was dysarthria in one and nonfluent speech in the other on formal testing. In addition, there was volitional swallowing deficit in patient 11 with right-sided numbness. Both patients had distal arm and hand weakness, an increased ankle reflex, and extensor plantar response.
Volitional facial paresis affects facial movements with voluntary effort, sparing activation on emotion. Emotional facial paresis is characterized by impaired activation of face muscles with emotion but normal voluntary activation. [1-5] We believe that our two patients had voluntary-emotional dissociative face palsy. The concept of parallel cortical representation is well established in sensory systems and increasingly accepted for motor function. Dissociation of voluntary and emotional facial movements serves as an excellent example as seen in our patients. Primary motor cortex in the precentral gyrus (M1) is active during voluntary movements, the supplementary motor area (SMA) has been considered essential for emotional innervation. [3]
A previous report of seven patients indicated that the lesions involving the frontal lobe white matter, the striatocapsular territory, the anterolateral thalamus and insula, the posterior thalamus and operculum, the mesial temporal lobe and insula, and the posterior thalamus may also cause dissociative voluntary-emotional facial palsy. [1]
Anatomic tract-tracing experiments in nonhuman primates have demonstrated that corticofacial projections arise from six distinct cortical motor areas: M1 (Brodmann area 4/F1), SMA (M2/6m/F3), rostral and caudal cingulate motor cortices (M3 and M4/24c and 23c), and dorsal and ventral lateral premotor cortices (6d and 6v/F2 and F4). [6] These sites have counterparts in distinct cortical areas of the human brain perhaps with homologous functions. [5]
Sparing of pathways in the subinsular area originating from SMA may explain our patient's intact emotional facial expression. Clinico-radiologic observations of central facial palsy help to corroborate or refute experimental data concerning parallel motor pathways.
References
1. Hopf HC, Muller-Forell W, Hopf NJ. Localization of emotional and volitional facial paresis. Neurology 1992;42:1918�1923.
2. Ross RT, Mathiesen R. Images in clinical medicine. Volitional and emotional supranuclear facial weakness. N Engl J Med 1998;338:1515.
3. Jox R, Bruning R, Hamann G, Danek A. Volitional facial palsy after a vascular lesion of the supplementary motor area. Neurology 2004;63:756- 757.
4. Root AA, Stephens JA. Organization of the central control of muscles of facial expression in man. J. Physiol 2003;549:289-298.
5. Wild B, Rodden FA, Grodd W, Ruch W. Neural correlates of laughter and humour. Brain 2003; 126:2121-2138.
6. Morecraft RJ, Louie JL, Herrick JL, Stilwell-Morecraft KS. Cortical innervation of the facial nucleus in the non-human primate: A new interpretation of the effects of stroke and related subtotal brain trauma on the muscles of facial expression. Brain 2001;124:176-208.

Strokes in the subinsular territory: Clinical, topographical, and etiological patterns 21 April 2005

Douglas J. Lanska,
VA Medical Center
500 E. Veterans St., Tomah, WI 54660
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Re: Strokes in the subinsular territory: Clinical, topographical, and etiological patterns

Douglas.Lanska{at}med.va.gov Douglas J. Lanska

Kumral et al recently described the clinical manifestations of 11 patients with strokes in the subinsular territory. [1] Eight (73%) had facial paresis, but it is not clear from the report whether there was automatic-voluntary dissociation as can be seen with insular and anterior opercular infarcts. Were volitional, emotional, and automatic facial movements similarly affected in these patients?
The authors note that dysphagia and anarthria can be seen in bilateral cortical lesions involving the insular cortex as described by Foix, Chavany, and Marie in 1926. [2-4] The anterior opercular syndrome (Foix-Chavany-Marie syndrome or facio-pharyngo-glosso-masticatory diplegia) is characterized by bilateral voluntary central pseudobulbar paresis of the muscles innervated by the 5th, 7th, 9th, 10th and 12th cranial nerves with preservation of emotional or automatic movements. Emotional facial paresis (i.e., impaired activation of face muscles with emotion but normal voluntary activation) may also be seen with insular and opercular lesions. [5]
References
1. Kumral E, �zdemirkiran T, Alper Y. Strokes in the subinsular territory: clinical, topographical, and etiological patterns. Neurology 2004;63:2429-2432.
2. Foix C, Chavany JA, Marie J. Dipl�gie facio-linguo-masticatrice d�origine cortico-sous-corticale sans paralysie des membres. Rev Neurol 1926;33:214-219.
3. Foix C, Chavany JA. Dipl�gie faciales (facio-linguo-pharingo- masticatrices), d'origine corticale, avec quelques considerations sur les paralysies pseudo-bulbaires et la localization des centres corticaux de l'estr�mit� c�phalique. Ann Med 1926;20:480-98.
4. Mao C-C, Coull BM, Golpher LAC, Rau MT. Anterior opercular syndrome. Neurology 1989;39:1169-1172.
5. Hopf HC, Muller-Forell W, Hopf NJ. Localization of emotional and volitional facial paresis. Neurology 1992;42:1918-1923.

Strokes in the subinsular territory: Clinical, topographical, and etiological patterns 1 March 2005

Yasuo Iwasaki,
Toho University Omori Hospital
6-11-1 Omorinishi Ota-ku Tokyo 143-8541 JAPAN,
Osamu Igarashi, Yasumitsu Ichikawa and Ken Ikeda
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Re: Strokes in the subinsular territory: Clinical, topographical, and etiological patterns

yaso{at}med.toho-u.ac.jp Yasuo Iwasaki, et al.

We read the recent article concerning subinsular stroke (SubIS) by Kumral et al with great interest. [1] They reported 11 patients with subIS and its clinical, topographical, and etiological patterns. We studied first-ever stroke patients, and found four cases in whom responsible lesions were restricted to the subinsular territory. All our patients exhibited faciobrachiocrural motor deficit only. There was no sensory impairment, dizziness, dysarthria or dysphagia. Aphasia and aphonia were absent in our patients. All had hypertension but no prominent internal carotid (IC) stenosis or cardioembolism (CE).
At stroke onset, two patients showed transient disturbance of consciousness. Motor deficits were very mild and hemiparesis was fully recovered within a few months. Kumral et al evaluated stroke patients with first-ever attack. We see patients with multiple cerebral infarctions whose lesions occur in the subinsular territory, and we think restricted stroke lesion in the subinsular territory is not uncommon. Two of four of our patients exhibited transient disturbance of consciousness. We would like to inquire whether Kumral et al's patients showed alternation of consciousness. There were no cases with prominent IC stenosis and CE in our patients and it is conceivable there is an ethnic difference for the underlying condition for stroke.
Prognosis is good for subIS. Stroke in the subinsular territory [2,3] is not familiar to the general physician and because many internists see stroke patients in the emergency department, the possibility of subIS should be considered.
References
1. Kumral E, �zdemirkiran T, Alper Y. Strokes in the subsinsular territory: clinical, topographical, and etiological patterns. Neurology 2004; 63: 2429-2432.
2. Bladin CF, Chambers BR: Clinical features, pathogenosis, and computed topographic characteristics of internal watershed infarction. Stroke 1993;24:1925-1932.
3. Wong E, Pallicino PM, Benedict R. Deep cerebral infarcts extending to the subinsular region. Stroke 2001; 32: 2272-2277.

Reply to Iwasaki et al 1 March 2005

Emre Kumral,
Stroke and Neuropsychology Unit, Department of Neurology, Ege University
Bornova, Izmir, 35100, Turkey
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Re: Reply to Iwasaki et al

ekumral{at}med.ege.edu.tr Emre Kumral

We thank Iwasaki et al for their interest in our article. Subinsular stroke without involvement of the insular cortex and striatum is very rare (%0.4 of patients in our registry). In more than half of our cases, there was a source of embolism originating either from the large arteries or cardiac arrhythmia.
It is conceivable that ethnic differences or other factors may play a role in the pathogenesis of subinsular stroke. The subinsular area is a long and relatively large area beginning from the peri-caudate nucleus to the temporal horn of lateral ventricle. Faciobrachial or faciobrachiocrural somatosensory symptoms may develop depending on the corticobulbaire or thalamo-cortical pathways involved. The insula and routes crossing this area are also responsible for volitional swallowing, gustatory functions, and speech.
There are previous reports about dysphagia, gustatory dysfunctions, and speech arrest following insular and subinsular lesions. [1,2,3] Transient disturbance of consciousness exhibited by Iwasaki et al's patients may be the result of multiple or large infarcts involving neighboring structures which could not be seen at the early stages of ischemia by conventional MRI techniques.
There are few reports on the consciousness disturbance due to deep cerebral infarcts extending to the subinsular region. We agree that subinsular stroke may not be recognized by internists or even by neurologists who do not consider stroke subgroups.
References
1.Cereda C, Ghika J, Maeder P, Bogousslavsky J. Strokes restricted to the insular cortex. Neurology 2002,59:1950-1955
2.Mann G, Hankey GJ, Cameron D.Swallowing function after stroke: prognosis and prognostic factors at 6 months. Stroke 1999,30:744-748
3.Augustine JR.Circuitry and functional aspects of the insular lobe in primates including humans. Brain Res Rev 1996;22:229-244 4.Wong E, Pallicino PM, Benedict R. Deep cerebral infarcts extending to the subinsular region. Stroke 2001; 32: 2272-2277.