Novel Anatomic Classification of Spontaneous Thalamic Hemorrhage Classified by Vascular Territory of Thalamus.

BACKGROUND: Spontaneous thalamic hemorrhage has increased in incidence in recent years. Analysis of the characteristics of thalamic hemorrhage was based on the vascular territories of the thalamus. METHODS: Retrospective analysis included 303 consecutive patients with spontaneous thalamic hemorrhage. Thalamic hemorrhage was classified into 4 types: anterior type (supplied mainly by the tuberothalamic artery), medial (mainly paramedian thalamic-subthalamic artery), lateral (mainly thalamogeniculate artery), and posterior (mainly posterior choroidal artery). The baseline characteristics, complications, and functional outcomes were assessed. RESULTS: The anterior type was found in 10 patients (3.3%), the medial type in 47 (15.5%), the lateral type in 230 (75.9%), and the posterior type in 16 (5.3%). Intracerebral hemorrhage volume was smallest in the anterior type, and significantly smaller than in the medial (P = 0.002) and lateral types (P < 0.001). Intraventricular hemorrhage (IVH) or acute hydrocephalus was significantly associated with the medial type (P < 0.01 or P < 0.01, respectively). Non-IVH or non-acute hydrocephalus was significantly associated with the anterior (P < 0.05 or P < 0.05, respectively) and lateral (P < 0.05 or P < 0.05, respectively) types. Emergency surgery was correlated only with the medial type (P < 0.01). The independent predictors of poor outcome were age (odds ratio [OR], 1.07; P = 0.002), admission National Institutes of Health Stroke Scale score (OR, 1.32; P < 0.001), and type of thalamic hemorrhage (OR, 2.08; P = 0.038). CONCLUSIONS: The present study proposed a novel anatomic classification of thalamic hemorrhage according to the major thalamic vascular territories.

[Localization of the pyramidal tract in the internal capsule: relationship between CT classification of thalamic hemorrhage and motor weakness].

To better understand the pyramidal tract of the internal capsule, we evaluated the relationship between the localization of thalamic hemorrhage and motor weakness. On an axial CT scan at the level of the pineal body, two lines were drawn as follows: line-a between the lateral edge of the anterior horn and the lateral edge of the trigone, line-b vertical to the sagittal line and passing the midpoint of the third ventricle. The location of the hematoma was classified into three types according to localization of the center of the hematoma and lateral extension beyond line-a as follows: type A (anterior), type P (posterior) and type PL (postero-lateral). Discrepancy of motor weakness between upper extremities and lower extremities was higher in patients with hematoma of type P and type PL (p < 0.05) than in those with hematoma of type A. Improvement of motor weakness on discharge was higher in patients with type P (p < 0.01) than in those with type A. We concluded that most of the pyramidal tract fibers were located in the third quarter of the posterior limb of the internal capsule but a small number of pyramidal tract fibers were located in the anterior two-thirds of it. A greater number of cortico-spinal fibers to the upper extremities than to the lower extremities occupy the third quarter of the posterior limb of the internal capsule.

[Practical CT classification for thalamic hemorrhage: relationship between localization of hematoma and prognosis].

It is not easy to predict functional outcome in patients with acute-stage thalamic hemorrhage. We analysed 100 cases of hypertensive thalamic hemorrhage less than 4 cm in diameter, and devised a practical CT classification for predicting the patients' prognoses. On an axial CT scan at the level of the pineal body, four lines were drawn as follows: line (a) between the lateral edge of the anterior horn and the midpoint of the third ventricle; line (b) vertical line to the sagittal line from the midpoint of the third ventricle; line (c) between the lateral edge of the trigone and the midpoint of the third ventricle; line (d) between the lateral edge of the anterior horn and the lateral edge of the trigone. The location of hematoma was divided into three types according to lateral extension as follows: type A (anterior type), center of hematoma located between line (a) and line (b); type P (posterior type), center of hematoma located between line (b) and line (c), and external margin of hematoma localized medial to line (d); type PL (postero-lateral type), center of hematoma located between line (b) and line (c), and showing lateral extension beyond line (d). Then, the correlation between hematoma location and severity of motor paresis at onset and its prognosis was investigated. Severe hemiparesis (MMT: 0-2) was observed in 15.3% of patients with type A, 21.8% with type P, and 59.3% with type PL hematoma in the acute stage.(ABSTRACT TRUNCATED AT 250 WORDS)

Analysis of the prion protein gene in thalamic dementia.

Thalamic degenerations or dementias are poorly understood conditions. The familial forms are (1) selective thalamic degenerations and (2) thalamic degenerations associated with multiple system atrophy. Selective thalamic degenerations share clinical and pathologic features with fatal familial insomnia, an autosomal dominant disease linked to a mutation at codon 178 of the prion protein (PrP) gene that causes the substitution of asparagine for aspartic acid (178Asn mutation). We amplified the carboxyl terminal coding region of the PrP gene from subjects with selective thalamic dementia or thalamic dementia associated with multiple system atrophy. Three of the four kindreds with selective thalamic dementia and none of the three kindreds with thalamic dementia associated with multiple system atrophy had the PrP 178Asn mutation. Thus, analysis of the PrP gene may be useful in diagnosing the subtypes of thalamic dementia. Moreover, since selective thalamic dementia with the PrP 178Asn mutation and fatal familial insomnia share clinical and histopathologic features, we propose that they are the same disease.

Los síndromes de lesión talámica

En la unidad de Neurología del Centro Hospitalario San Juan de Dios de Bogotá, durante cuatro años (1986 a 1989), se estudiaron en forma consecutiva 25 pacientes con lesiones talámaticas no fatales. Se registraron los hallazgos neurológicos, neurosicológicos y neurooftalmológicos y los diagnósticos se confirmaron por tomografía computarizada (TC). Fueron 14 mujeres y 11 varones con una edad promedio de 52.5 y un rango de 25 a 84 años. La lesión talámica fue de origen vascular en 24 casos, ocho por infarto isquémico, cuatro por infarto hemorrágico y 12 con hematomas parenquimatosos. Diecisiete pacientes tenían hipertensión arterial sistémica y el único factor de riesgo en otros dos era el consumo de cocaína base (basuco). Ocho infartos se presentaron en el tálamo derecho, 12 en el izquierdo y cinco pacientes tuvieron lesiones bilaterales, uno de ellos con un glioma complobado por biopsia. En 5 pacientes con lesiónes bilateral se observó el síndrome del "Tope" de la arteria basilar, por compromiso del pedículo retromamilar; en todos ellos encontramos alteraciones sensitivomotoras, cerebelosas, oculomotoras bilaterales y demencia. Solamente un paciente presentó el clasicó síndrome de hiperpatía (Dejerine-Roussy). En los restantes se observaron asociaciones de síndromes sensitivomotores, cerebelosos, neurooftalmológicos, neuropsicológicos, y del comportamiento motor que remedan con frecuencia los hallazgos clínicos de la alteración cortical frontal, temporal o parietal.

Clinical course of spontaneous gangliothalamic hemorrhage in the acute period--who requires surgical removal?

We analyzed the clinical courses of 93 consecutive patients with gangliothalmic hemorrhage for the first three weeks after the ictus and investigated the factors affecting the clinical course and the final outcome. The clinical status was assessed daily using the Glasgow Coma Score (GCS) and patients were divided into two groups according to the clinical course; Group I included those who improved and Group II consisted of patients who deteriorated. There were 44 patients (47.3%) in Group I and 49 patients (52.7%) in group II. Each group was subdivided into the conservative group and the surgical group. In Group I only eight patients (18.2%) received surgery while twenty-five patients (51.0%) received surgery in Group II. Clinical features and computed tomography characteristics of these four groups were compared. Our results suggested that the surgery is rarely required for patients 1) whose GCS values are 12 or more without deterioration; 2) with hematomas smaller than 3 cm in diameter or 20 ml in volume; 3) with midline shifts of less than 3 mm, and 4) whose subtypes of the hematomas are P1, P2a, T1, T2a, and T2b. For proper comparison of the results of medical and surgical treatment, the patient population should include the patients 1) who became deteriorated progressively regardless of initial GCS values; 2) whose GCS values are below 12; 3) with hematomas larger than at least 3cm in diameter or 20ml in volume; 4) with midline shift of more than 3mm, and 5) whose subtypes of the hematoma are P2b or GT.

Thalamic pain syndrome of Dejérine-Roussy. Differentiation of four subtypes assisted by somatosensory evoked potentials data.

In 30 patients with a thalamic vascular lesion and clinical somatosensory disturbances in the opposite hemibody without hemiplegia, four nosological groups were identified: group 1 had no central pain but complete hemianesthesia and loss of cortical somatosensory evoked potentials (SEPs) on the affected side (analgic thalamic syndrome). Group 2 had central pain, severe hypoesthesia, and loss of cortical SEPs. Group 3 had central pain and hypoesthesia, with cortical SEPs present, although reduced or delayed on the affected side. Group 4 had central pain with preserved touch and joint sensations and normal SEPs (pure algetic thalamic syndrome). Clinical signs and SEP titration of the actual involvement of lemniscal pathways in these four groups of patients with thalamic syndrome are discussed in relation to current pathophysiology of central pain.

[Clinical manifestation of small thalamic hemorrhage].

CT scan is useful for the simultaneous evaluation of the relation between the thalamic lesions and the clinical manifestations. According to CT findings, twenty-three patients with thalamic hemorrhage measuring less than 2 cm in size could be classified into 4 groups: 1) anterior group--hematoma located in the anterior nuclear group, 2) medial group--hematoma located in the medial nuclear group, 3) lateral group--hematoma located in the lateral nuclear group close to the internal capsule, 4) posterior group--hematoma located in the pulvinar. The clinical manifestations of both the anterior and medial groups were characterized by the disturbance of consciousness followed by the mental impairment; the lateral group, by the hemiparesis or hemiplegia with the sensory disturbance, and the posterior group, especially with left thalamic lesions, by the speech disturbance. The motor palsy in cases of thalamic hemorrhage differed from that of putaminal hemorrhage: the patients with thalamic hemorrhage could move their fingers despite being unable to move their shoulders and elbows, or the motor weakness was more severe in their lower extremities than in their upper ones. As the sensory disturbance, the sensory impairment (hypesthesia) was frequently associated with the numbness (dysesthesia). The prognosis of motor palsy, ocular manifestations, and speech disturbance was good, whereas that of sensory and mental disturbance was not always good.

Somatosensory evoked potentials in patients with thalamic lesions.

Somatosensory evoked potentials (SEPs) were recorded in 20 patients with thalamic lesions confirmed by CT (10 with infarction, 10 with haemorrhage). The changes in SEP configuration are discussed in their relationship to clinical symptoms. Four types of SEP abnormality produced by thalamic lesion are distinguished: (1) "FF" type, (2) "N20/P23 dissociation" type, (3) "N18/N20 false shift" type, and (4) "reduced early component" type. It was shown that clinically similar lesions might produce different SEP patterns.