Rotatory Vertigo Caused by a Small Hemorrhage in the Superior Temporal Gyrus.

Rotatory vertigo is known to have not only peripheral causes, e.g., Meniere's disease, vestibular neuritis, and benign paroxysmal positional vertigo, but also central causes, e.g., stroke, hemorrhage, and tumor. In most cases, central rotatory vertigo is caused by a lesion in the brainstem or cerebellum, but rare cases with a cerebral lesion have also been reported. We herin describe a unique case with acute rotatory vertigo following a small hemorrhage in the left superior temporal gyrus, which probably led to a dysfunction of the visual-vestibular system.

Lower cardiac index levels relate to lower cerebral blood flow in older adults.

OBJECTIVE: To assess cross-sectionally whether lower cardiac index relates to lower resting cerebral blood flow (CBF) and cerebrovascular reactivity (CVR) among older adults. METHODS: Vanderbilt Memory & Aging Project participants free of stroke, dementia, and heart failure were studied (n = 314, age 73 ± 7 years, 59% male, 39% with mild cognitive impairment). Cardiac index (liters per minute per meter squared) was quantified from echocardiography. Resting CBF (milliliters per 100 grams per minute) and hypercapnia-induced CVR were quantified from pseudo-continuous arterial spin-labeling MRI. Linear regressions with ordinary least-square estimates related cardiac index to regional CBF, with adjustment for age, education, race/ethnicity, Framingham Stroke Risk Profile score (systolic blood pressure, antihypertensive medication use, diabetes mellitus, current cigarette smoking, left ventricular hypertrophy, prevalent cardiovascular disease [CVD], atrial fibrillation), APOE ε4 status, cognitive diagnosis, and regional tissue volume. RESULTS: Lower cardiac index corresponded to lower resting CBF in the left (ß = 2.4, p = 0.001) and right (ß = 2.5, p = 0.001) temporal lobes. Results were similar when participants with prevalent CVD and atrial fibrillation were excluded (left temporal lobe ß = 2.3, p = 0.003; right temporal lobe ß = 2.5, p = 0.003). Cardiac index was unrelated to CBF in other regions assessed (p > 0.25) and CVR in all regions (p > 0.05). In secondary cardiac index × cognitive diagnosis interaction models, cardiac index and CBF associations were present only in cognitively normal participants and affected a majority of regions assessed with effects strongest in the left (p < 0.0001) and right (p < 0.0001) temporal lobes. CONCLUSIONS: Among older adults without stroke, dementia, or heart failure, systemic blood flow correlates with cerebral CBF in the temporal lobe, independently of prevalent CVD, but not CVR.

Subgaleal Hematoma at the Contralateral Side of Scalp Trauma in an Adult.

BACKGROUND: Subgaleal hematoma (SGH), an abnormal accumulation of blood under the galeal aponeurosis of the scalp, is more commonly observed in newborns and children. According to previous cases, the etiology of SGH includes mild head trauma, vacuum-assisted vaginal delivery, contusion, and hair braiding or pulling. CASE REPORT: A 39-year-old healthy worker came to our emergency department (ED) due to scalp lacerations from an accident that caused severe twisting of his hair. He denied head contusion and was conscious upon arrival. Physical examination showed three lacerations over his right temporal area. The wounds depth extended to the skull, with a 10-cm subperiosteal pocket beneath the lacerations. Primary sutures were performed immediately under local anesthesia, not only for wound closure but also for hemostasis. However, he returned to our ED 3 h after the first visit for a newly developed soft lump over the left side of his forehead. Computed tomography scan of brain illustrated a huge and diffuse SGH in the left temporal region with extension to periorbital region. Although the option of incision and drainage was discussed with a neurosurgeon and a search for some case reports was done, most of the hematoma could be self-limited. Conservative management with non-elastic bandage packing direct compression was applied. The patient was then admitted for close observation and conservative treatment for 1 week. There was no recurrence of SGH in the following 3 months. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: SGH is an uncommon phenomenon that is caused by tearing of the emissary veins in the loose areolar tissue located beneath the galeal aponeurosis. Conservative treatment with bandage compression is recommended for SGH. Surgery is reserved for cases where non-invasive management fails or severe complications.

[Tentorial Dural Arteriovenous Fistula Successfully Treated with Transvenous Embolization Using a Double Catheterization Technique through Venous Drainage:A Case Report].

BACKGROUND: Tentorial dural arteriovenous fistulas(dAVFs)are a rare clinical entity accounting for less than 10% of all intracranial dAVFs. Because these lesions are characterized by high hemorrhagic risk, aggressive treatment should be considered. Although the number of reported cases treated with endovascular transarterial embolization(TAE)using glue has been increasing, little is known about the transvenous approach. Here, we report the case of a patient with a tentorial dAVF who was successfully treated with transvenous embolization(TVE)through venous drainage using a double catheterization technique. CASE PRESENTATION: A 68-year-old male patient who had a history of left putaminal hemorrhage treated with a craniotomy was diagnosed with a tentorial dAVF on a magnetic resonance angiogram. Because the patient refused another craniotomy for surgical interruption of the dAVF, an endovascular approach was considered. We first attempted to perform TAE with glue, but catheterization into the tortuous meningohypophyseal trunk failed. We then performed a TVE of the venous drainage near the shunt with detachable coils and achieved complete obliteration of the fistula. During coil embolization of the venous drainage, insertion of small coils near the shunt was supported by another anchor coil that was delivered using a double catheterization technique. CONCLUSIONS: The method of TVE through venous drainage using a double catheterization technique, which involved placing coils in the fragile drainage vein, was safe and effective in a case of tentorial dAVF. This technique should be considered as another option for the management of complex tentorial dAVFs.

Rete mirabile associated with pial arteriovenous fistula: imaging features with literature review.

A rete mirabile is a vascular network of intercommunicating small arteries or arterioles that replace the definitive adult artery supplying the brain. It supplies the brain in lower mammals but is not seen in normal human embryological development. A 26-year-old man presented with worsening tinnitus that was interfering with his sleep. On CT and digital subtraction angiography he was found to have a temporal lobe pial arteriovenous fistula with bilateral carotid and vertebral rete mirabile. The patient was offered open surgical and endovascular treatment options for pial arteriovenous fistula but he refused both and opted for conservative medical management. At 6-month follow-up he continued to have pulsatile tinnitus but was otherwise neurologically normal. We present the first described association of rete mirabile with pial arteriovenous fistula and discuss its clinical presentation and imaging features, with a review of the literature for bilateral carotid and vertebral rete mirabile.

Density heterogeneity and fluid-blood levels in patients aged over 55 with lobar hematoma.

BACKGROUND: Density heterogeneity and fluid-blood levels (FBLs) are frequently seen on acute CT scans of deep brain hemorrhage. Our aim was to analyze the density heterogeneity and FBLs seen on acute/subacute CT in patients aged>55 with lobar haemorrhage (LH), and to study the relationship of these brain abnormalities with other parameters, including cerebral amyloid angiopathy (CAA)-related abnormalities. METHODS: This was an observational study and retrospective analysis of early CT scans (<7 days) in patients aged>55 years with acute lobar hemorrhage who, between 2012 and 2015, were entered into our stroke database. A total of 37 LH episodes (without trauma, abnormal coagulation/platelet counts, vascular malformation, tumor or vasculitis) in 35 patients were analyzed. Other studied parameters were gender, age, history of hypertension, blood pressure on admission, prior antiplatelet treatment, aPTT, PTT, platelet count, hematocrit, timing of first CT, LH volume, involved lobe, cortical superficial siderosis, microbleeds, chronic LH and CAA (classic and modified Boston) criteria. CAA-related abnormalities seen on MRI were also scored. RESULTS: Overall, in 26 LH episodes (70%), CT was performed within 24h. Density heterogeneity and FBLs were seen in 19 (51%) and 9 (24%) LH episodes, respectively. Also, according to classic and modified Boston criteria, 18 (51%) and 24 (69%) patients, respectively, fulfilled criteria for probable/definite CAA. As for the presence of FBLs, a statistically significant association was found with both the presence of probable/definite CAA according to modified Boston criteria (P=0.033) and the presence of superficial siderosis (P=0.019). CONCLUSION: Density heterogeneity and, to a lesser degree, FBLs are frequently seen in patients aged>55 with LH. FBLs may also be associated with CAA-related hemorrhage.

Lesion-to-Eloquent Fiber Distance Is a Crucial Risk Factor in Presurgical Evaluation of Arteriovenous Malformations in the Temporo-occipital Junction.

OBJECTIVE: Temporo-occipital junction arteriovenous malformations (TOJ-AVMs) do not often involve eloquent brain cortex, but rather exist beside functional fiber tracts. The objective of this study was to determine the outcomes after surgical treatment in patients with TOJ-AVMs and to identify risk factors associated with postoperative neurologic deficits. METHODS: We retrospectively studied 41 patients with TOJ-AVMs. All patients underwent preoperative diffusion tensor imaging. Every potentially involved function (visual field and language) was studied as an independent function object (FO). The function-related optic radiation or arcuate fasciculus was tracked. Lesion-to-eloquent fiber distances (LFDs) were analyzed in regard to postoperative neurologic deficits. The areas under the receiver operating characteristic curves were compared. RESULTS: There were 58 FOs analyzed. Of these, 26 (44.8%) FOs led to short-term neurologic deficits, and 21 (36.2%) FOs resulted in long-term neurologic deficits. LFD was a significant predictor of short-term (P = 0.002) and long-term (P = 0.007) neurologic deficits. The Spetzler-Martin (S-M) score was associated with short-term neurologic deficits (P = 0.045), but it was not associated with long-term neurologic deficits. The area under the receiver operating characteristic curve of LFD was higher than that of the S-M score in predicting short-term neurologic deficits (0.89 vs. 0.72, P = 0.04) and long-term neurologic deficits (0.90 vs. 0.62, P = 0.002). The cutoff point for LFD in predicting long-term neurologic deficits was 3.10 mm. CONCLUSIONS: Patients with TOJ-AVMs have a high risk of surgical morbidity, although they often have relatively low S-M scores; LFD is a crucial risk factor associated with postoperative neurologic deficits in patients with TOJ-AVMs.

Temporal Cerebral Microbleeds Are Associated With Radiation Necrosis and Cognitive Dysfunction in Patients Treated for Nasopharyngeal Carcinoma.

PURPOSE: Radiation therapy for patients with nasopharyngeal carcinoma (NPC) may be complicated with radiation-induced brain necrosis (RN), resulting in deteriorated cognitive function. However, the underlying mechanism of this phenomenon remains unclear. This study attempts to elucidate the association between cerebral microbleeds (CMBs) and radiation necrosis and cognitive dysfunction in NPC patients treated with radiation therapy. METHODS AND MATERIALS: This cross-sectional study included 106 NPC patients who were exposed to radiation therapy (78 patients with RN and 28 without RN). Sixty-six patients without discernable intracranial pathology were included as the control group. CMBs were confirmed using susceptibility-weighted magnetic resonance imaging. Cognitive function was accessed using Montreal Cognitive Assessment. Patients with a total score below 26 were defined as cognitively dysfunction. RESULTS: Seventy-seven patients (98.7%) in the RN group and 12 patients (42.9%) in the non-RN group had at least 1 CMB. In contrast, only 14 patients (21.2%) in the control group had CMBs. In patients with a history of radiation therapy, CMBs most commonly presented in temporal lobes (76.4%) followed by cerebellum (23.7%). Patients with RN had more temporal CMBs than those in the non-RN group (37.7 ± 51.9 vs 3.8 ± 12.6, respectively; P<.001). The number of temporal lobe CMBs was predictive for larger volume of brain necrosis (P<.001) in multivariate linear regression analysis. Although cognitive impairment was diagnosed in 55.1% of RN patients, only 7.1% of non-RN patients sustained cognitive impairment (P<.001). After adjusting for age, sex, education, period after radiation therapy, CMBs in other lobes, and RN volume, the number of temporal CMBs remained an independent risk factor for cognitive dysfunction (odds ratio [OR]: 1.03; 95% confidence interval [CI]: 1.01-1.04; P=.003). CONCLUSIONS: CMBs is a common radiological manifestation in NPC patients with RN. The number of temporal CMBs is independently associated with increased likelihood of cognitive dysfunction in patients with RN.

EEG-fMRI in the presurgical evaluation of temporal lobe epilepsy.

OBJECTIVE: Drug-resistant temporal lobe epilepsy (TLE) often requires thorough investigation to define the epileptogenic zone for surgical treatment. We used simultaneous interictal scalp EEG-fMRI to evaluate its value for predicting long-term postsurgical outcome. METHODS: 30 patients undergoing presurgical evaluation and proceeding to temporal lobe (TL) resection were studied. Interictal epileptiform discharges (IEDs) were identified on intra-MRI EEG and used to build a model of haemodynamic changes. In addition, topographic electroencephalographic correlation maps were calculated between the average IED during video-EEG and intra-MRI EEG, and used as a condition. This allowed the analysis of all data irrespective of the presence of IED on intra-MRI EEG. Mean follow-up after surgery was 46 months. International League Against Epilepsy (ILAE) outcomes 1 and 2 were considered good, and 3-6 poor, surgical outcome. Haemodynamic maps were classified according to the presence (Concordant) or absence (Discordant) of Blood Oxygen Level-Dependent (BOLD) change in the TL overlapping with the surgical resection. RESULTS: The proportion of patients with good surgical outcome was significantly higher (13/16; 81%) in the Concordant than in the Discordant group (3/14; 21%) (χ(2) test, Yates correction, p=0.003) and multivariate analysis showed that Concordant BOLD maps were independently related to good surgical outcome (p=0.007). Sensitivity and specificity of EEG-fMRI results to identify patients with good surgical outcome were 81% and 79%, respectively, and positive and negative predictive values were 81% and 79%, respectively. INTERPRETATION: The presence of significant BOLD changes in the area of resection on interictal EEG-fMRI in patients with TLE retrospectively confirmed the epileptogenic zone. Surgical resection including regions of haemodynamic changes in the TL may lead to better postoperative outcome.

Arteries and Veins of the Sylvian Fissure and Insula: Microsurgical Anatomy.

We present a vascular anatomical study of the arteries and veins of the sylvian fissure and insula.A good knowledge of the sylvian fissure, the insula, and their vascular relationship would seem mandatory before performing surgery in this area, whatever the type of surgery (aneurysms, arteriovenous malformations, insular tumors).We start with the sylvian fissure and insula morphology, followed by the MCA description and its perforators, with special attention paid to the insular perforators. We demonstrate that the long insular perforators penetrating in the superior part of the posterior short gyrus and long gyri vascularize, respectively, the corticonuclear and corticospinal fasciculi. We particularly insist too on three anatomical constants regarding the vascularization of the insula, already described in the literature: The superior periinsular sulcus is the only sulcus on the lateral surface of the brain without an artery along its axis; the superior branch of the MCA supplies the anterior insular pole and both the anterior and middle short gyri in 100 % of cases; in at least 90 % of cases, the artery that supplied the central insular sulcus continued on to become the central artery.We end with the anatomical study of the veins and cisterns.

Thrombophlebitis of the temporal vein as an extracranial complication of acute bacterial rhinosinusitis.

A 39-year-old white man presented with a swollen left upper eyelid secondary to progressive acute bacterial rhinosinusitis (ABRS). Physical examination found a 40% reduction in vision in the left eye and right-sided erythematous temporal swelling with tenderness to palpation. Computed tomography revealed the presence of an inflammatory lesion in the left orbit. Duplex ultrasonography demonstrated a thrombotic occlusion in the right superficial temporal vein (STV). For treatment of the complicated ARBS, the patient received intravenous antibiotics and underwent surgery. The STV thrombophlebitis was treated with low-molecular-weight heparin. Postoperatively, the patient recovered completely and his vision normalized; 10 days later, duplex ultrasonography showed a patent STV. The development of contralateral STV thrombophlebitis is conceivably facilitated by venous anastomoses of the scalp in the front of the head. As a result, embolic spread would be a possible complication of infectious ABRS foci communicating with intraorbital and pericranial veins. To the best of our knowledge, this is the first reported case of such a complication of ARBS in the literature.

[Meningioangiomatosis: a clinicopathological study of five cases].

OBJECTIVE: To investigate the clinicopathologic characteristics of meningioangiomatosis (MA). METHODS: Five cases of MA were evaluated morphologically by HE and immunohistochemistry on formalin-fixed paraffin-embedded tissue. Clinical information was also obtained. The literature was reviewed. The clinical pathology and biological behavior of MA were discussed. RESULTS: Five cases of MA were reported, arising in three males and two females, with an age range of 16 to 26 years at diagnosis. All five subjects had intractable seizure disorders, and the duration of illness ranged from 8 months to 18 years. The lesions were resected from the frontal lobe in four patients, and from the temporal lobe in one. All the lesions were confined to the cortex, firm in consistency, without capsules and had poor blood supply. There was focal involvement of the overlying leptomeninges. Microscopically, they showed characteristic features of MA, such as proliferating microvessels with perivascular cuffs of spindle-cell within the cortex. Some had numerous calcifications, others showed acidophilic granular bodies. The cells were positive for EMA and vimentin by immunohistochemistry, and for reticulin by histochemical staining. CONCLUSIONS: MA is a rare, benign hamartomatous lesion of the central nervous system. It usually presents as plaque-like or nodular mass in the cerebral cortex and the overlying leptomeninges, consisting of meningovascular proliferation and leptomeningeal calcification. In some cases the lesion may show perivascular proliferation of elongated spindle-shaped cells. MA usually affects children and young adults, and is located in the frontal or temporal lobes with variable involvement of the overlying leptomeninges. Clinically, most of sporadic cases have a long history of intractable seizures despite multiantiepileptic drugs. MA has also been reported to coexist with arteriovenous malformations,meningiomas and other tumorous lesions.

Radiosurgery for temporal lobe arteriovenous malformations: effect of temporal location on seizure outcomes.

OBJECT: The temporal lobe is particularly susceptible to epileptogenesis. However, the routine use of anticonvulsant therapy is not implemented in temporal lobe AVM patients without seizures at presentation. The goals of this case-control study were to determine the radiosurgical outcomes for temporal lobe AVMs and to define the effect of temporal lobe location on postradiosurgery AVM seizure outcomes. METHODS: From a database of approximately 1400 patients, the authors generated a case cohort from patients with temporal lobe AVMs with at least 2 years follow-up or obliteration. A control cohort with similar baseline AVM characteristics was generated, blinded to outcome, from patients with non-temporal, cortical AVMs. They evaluated the rates and predictors of seizure freedom or decreased seizure frequency in patients with seizures or de novo seizures in those without seizures. RESULTS: A total of 175 temporal lobe AVMs were identified based on the inclusion criteria. Seizure was the presenting symptom in 38% of patients. The median AVM volume was 3.3 cm3, and the Spetzler-Martin grade was III or higher in 39% of cases. The median radiosurgical prescription dose was 22 Gy. At a median clinical follow-up of 73 months, the rates of seizure control and de novo seizures were 62% and 2%, respectively. Prior embolization (p = 0.023) and lower radiosurgical dose (p = 0.027) were significant predictors of seizure control. Neither temporal lobe location (p = 0.187) nor obliteration (p = 0.522) affected seizure outcomes. The cumulative obliteration rate was 63%, which was significantly higher in patients without seizures at presentation (p = 0.046). The rates of symptomatic and permanent radiation-induced changes were 3% and 1%, respectively. The annual risk of postradiosurgery hemorrhage was 1.3%. CONCLUSIONS: Radiosurgery is an effective treatment for temporal lobe AVMs. Furthermore, radiosurgery is protective against seizure progression in patients with temporal lobe AVM-associated seizures. Temporal lobe location does not affect radiosurgery-induced seizure control. The low risk of new-onset seizures in patients with temporal or extratemporal AVMs does not seem to warrant prophylactic use of anticonvulsants.

A multimodal mapping study of conduction aphasia with impaired repetition and spared reading aloud.

The present study explores the functional neuroanatomy of the phonological production system in an Italian aphasic patient (SP) who developed conduction aphasia of the reproduction type following brain surgery. SP presented with two peculiar features: (1) his lesion was localized in the superior temporal gyrus, just posterior to the primary auditory cortex and anterior/inferior to and neighboring the Sylvian parietal temporal (Spt) area, and (2) he presented with severely impaired repetition and spelling from dictation of words and pseudowords but spared reading-aloud of words and pseudowords. Structural, functional, fiber tracking and intraoperative findings were combined to analyze SP's pattern of performance within a widely used sensorimotor control scheme of speech production. We found a dissociation between an interrupted sector of the arcuate fasciculus terminating in STG, known to be involved in phonological processing, and a part of the arcuate fasciculus terminating in MTG, which is held to be involved in lexical-semantic processing. We argue that this phonological deficit should be interpreted as a disorder of the feedback system, in particular of the auditory and somatosensory target maps, which are assumed to be located along the Spt area. In patient SP, the spared part of the left arcuate fasciculus originating in MTG may support an unimpaired reading performance, while the damaged part of the left arcuate fasciculus originating in STG may be responsible for his impaired repetition and spelling from dictation.

Effectiveness of intraoperative indocyanine green videoangiography in direct surgical treatment of pediatric intracranial pial arteriovenous fistula.

Intracranial pial arteriovenous fistulas (AVFs) are rare cerebrovascular lesions. The authors report a rare case of pediatric pial AVF treated by direct disconnection with the aid of indocyanine green (ICG) videoangiography. A 3-year-old girl presented with developmental problems. Magnetic resonance imaging revealed brain atrophy and an anomalous left temporal vascular mass. Angiography showed a high-flow pial AVF in the early arterial phase fed by the M1 portion of the left middle cerebral artery and draining into the superficial sylvian vein and the vein of Trolard with a large varix. Given that her fistula was located in a superficial region that was easily accessible by craniotomy, the authors successfully disconnected her pial AVF by direct surgery aided by ICG videoangiography, which clearly confirmed the shunting point. In this report, the authors discuss the existing literature and compare the relative merits of endovascular versus surgical options for the treatment of pial AVF.

Involuntary switching into the native language induced by electrocortical stimulation of the superior temporal gyrus: a multimodal mapping study.

We describe involuntary language switching from L2 to L1 evoked by electro-stimulation in the superior temporal gyrus in a 30-year-old right-handed Serbian (L1) speaker who was also a late Italian learner (L2). The patient underwent awake brain surgery. Stimulation of other portions of the exposed cortex did not cause language switching as did not stimulation of the left inferior frontal gyrus, where we evoked a speech arrest. Stimulation effects on language switching were selective, namely, interfered with counting behaviour but not with object naming. The coordinates of the positive site were combined with functional and fibre tracking (DTI) data. Results showed that the language switching site belonged to a significant fMRI cluster in the left superior temporal gyrus/supramarginal gyrus found activated for both L1 and L2, and for both the patient and controls, and did not overlap with the inferior fronto-occipital fasciculus (IFOF), the inferior longitudinal fasciculus (ILF) and the superior longitudinal fasciculus (SLF). This area, also known as Stp, has a role in phonological processing. Language switching phenomenon we observed can be partly explained by transient dysfunction of the feed-forward control mechanism hypothesized by the DIVA (Directions Into Velocities of Articulators) model (Golfinopoulos, E., Tourville, J. A., & Guenther, F. H. (2010). The integration of large-scale neural network modeling and functional brain imaging in speech motor control.

Attenuation of regional cerebral blood flow during memory processing after coronary artery bypass surgery.

Reports of memory impairment after cardiac surgery are controversial. To address this controversy, we used positron emission tomography to examine changes in regional cerebral blood flow (rCBF) during memory processing before and after elective coronary artery bypass grafting surgery. In postoperative scans, we observed significantly reduced rCBF in 2 of the most important memory processing areas: the medial temporal lobe (P = 0.023) and the prefrontal cortex (P = 0.002). The results suggest postoperative attenuation of rCBF in brain areas involved in memory processing. These reductions could be used to evaluate severity of memory impairment after coronary artery bypass grafting surgery in patients at risk.

Vascular events after transsylvian selective amygdalohippocampectomy and impact on epilepsy outcome.

OBJECTIVE: Epilepsy surgery is a standard treatment option for medically intractable temporal lobe epilepsy. Selective amygdalohippocampectomy (SAH) and anterior temporal lobectomy (ATL) are two of the standard surgical procedures in these cases. We conducted a retrospective analysis of patients treated with SAH via a modified transsylvian approach in our epilepsy center between 2008 and 2011, and we analyzed the impact of adjacent procedure-related infarctions on seizure outcome in these patients. METHODS: Infarctions were detected by magnetic resonance imaging (MRI) within the first week postoperatively and by a second MRI 9 months after surgical intervention. Neuropsychological testing was performed preoperatively. Evaluation of seizure outcome and postoperative neuropsychological testing were conducted approximately 1 year after epilepsy surgery. Correlative clinical data were analyzed by retrospective chart review. RESULTS: The postoperative MRI revealed temporal infarctions in 47.9% (n = 23/48) and frontal infarctions in 10.4% (n = 5/48) of the patients. These vascular events were asymptomatic in terms of focal neurologic deficits. Of the patients, 68.5% (n = 37/54) were free of disabling seizures (Engel class I) 1 year after the procedure. Patients with temporal infarctions were significantly more often free of disabling seizures (Engel class I, p = 0.046) than patients without temporal infarctions. Neuropsychological testing indicated a deterioration in verbal memory after SAH in patients with infarctions on the language-lateralized hemisphere compared to patients without infarction (p = 0.011). All other tested neuropsychological categories showed no significant differences between patients with or without infarctions. SIGNIFICANCE: Our results indicate a surprisingly high number of procedure-related temporal infarctions after transsylvian SAH. Hence, the volume of nonfunctional "eliminated" tissue is enlarged unintentionally, which is a possible explanation for better seizure outcome in these patients. This result supports the notion that ATL is the favorable procedure for temporal lobe epilepsy compared to SAH in the nondominant hemisphere, as neuropsychological deficits are rarely to be expected.