Gamma knife radiosurgery for endocrine-inactive pituitary adenomas.

BACKGROUND: The goal of nonsecreting pituitary adenoma radiosurgery is to halt tumour growth and to maintain normal performance of the hypophysis and the functionally important structures around the sella. The effectiveness of gamma knife radiosurgery was evaluated. METHOD: Over a period of 10 years (1993-2003), 140 patients with nonsecreting pituitary adenoma were treated by Leksell gamma knife at our Centre. Seventy-nine of them were followed up for longer than 3 years. Their age range was 24-73 years, with a median of 54 years. Eighty-five percent of them had previous open surgery. Fifteen patients had adenoma contact with the optic tract. Fourteen patients had a normally functioning hypophysis, 48 patients had complete panhypopituitarism, while the rest retained partial functions of the normal hypophysis. Adenoma volumes ranged between 0.1 and 31.3, the median being 3.45 ccm. The marginal dose ranged between 12 and -35 Gy, with a median of 20 Gy. FINDINGS: The follow-up ranged from 36 to 122 months, with a median of 60 months. No adenoma growth was detected; 89% of treated adenomas decreased in size, with a median volume reduction of 61%. There was no perimeter vision impairment after radiosurgery, while 4 out of 52 patients with abnormal perimeter vision reported improvement. There was no impairment of oculomotor nerve function. Impairment of hypophysis function was observed in 2 patients. CONCLUSIONS: Radiosurgery has a reliable antiproliferative effect on nonsecreting pituitary adenomas. It is a safe treatment with a low risk of morbidity. Short contact between a nonsecreting pituitary adenoma and the optic pathway is not an absolute contraindication for Gamma knife radiosurgery.

[Secondary glaucoma treatment by means of Leksell gamma knife]. / Lécba sekundárního glaukomu Leksellovým gama nozem.

The authors followed up 107 eyes of 103 patients with the diagnosis of painful secondary glaucoma treated by irradiation of the ciliary body by means of Leksell gama knife (LGK Elekta Instruments AB). The goal was to decrease patient's subjective problems in to the treatment resistant and painful stages using non-invasive stereo tactic neurosurgical procedure. The final version of the irradiation schedule uses 8 mm collimators and the irradiation dose in blind eyes is 40 Gy at the maximum and 20 Gy at the peripheral treating 50% isodose; in partly sighted eyes it is 30 Gy at the maximum and 15 Gy at the peripheral treating 50% isodose. The follow up period was 3-80 months, (average 26 months). The lowering of the intraocular pressure to the not painful level was achieved in 56 eyes (52.2%) during the period of 1-8 weeks (median 4 weeks). The total disappearing of the pain after the treatment was noticed in 71 eyes (66.4%), partial reduction of the pain in 31 eyes (29%), and no effect was observed in 5 eyes. In all cases of neovascularization at least some decrease was noticed. The antiglaucomatous therapy was reduced in 42 patients (39.3%) 2-3 months after the irradiation, unchanged remained in 51 patients (47.7%). The stereotactic radiosurgical destruction of the ciliary body by means of Leksell gama knife, may reduce the pain, the intraocular pressure, and extensive medicament treatment in secondary painful glaucoma.

Gamma knife radiosurgery of skull base meningiomas.

Meningiomas are the most frequent benign tumors treated by gamma knife radiosurgery and the majority of them are located on the skull base. Between 1992 and 1999, 197 skull base-located meningiomas in 192 patients were treated by gamma knife in Prague. Contact with the chiasma or optic tract was not regarded as a contraindication for gamma knife radiosurgery and such contact was observed in 32% of the skull base meningiomas treated. 176 patients were monitored during a median of 36 months, of whom 73% showed a decrease in tumor volume; no change was observed in 25% and continued growth was observed in 2%. Neurodeficit improved in 63% of patients, temporary morbidity occurred in 11% and persistent morbidity remained in 4.5%. Radiosurgery induced edema in 11%. Significantly lower edema occurrence was observed after radiosurgery in patients with no history of edema prior to radiosurgery, where the tumor was located in the posterior skull base and where the dosage to the tumor margin was lower than or equal to 14 Gy. Radiosurgery of skull base meningiomas has been proven to be safe and efficient. We consider gamma knife treatment for skull base meningiomas to be the method of choice whenever tumors are within the volume limits and there is no need for an urgent decompressive effect from the open operation.

Radiosurgery for epilepsy associated with cavernous malformation: retrospective study in 49 patients.

OBJECTIVE: Microsurgical resection of a cavernous malformation (CM) with or without associated cortical resection can provide efficient treatment of drug-resistant associated epilepsy. To explore the potential alternative role of radiosurgery and to evaluate its safety and efficacy for this indication, we conducted a retrospective multicenter study. METHODS: We retrospectively reviewed the files of patients with long-lasting drug-resistant epilepsy, presumably caused by CM, who were treated by gamma knife (GK) surgery for the control of their epilepsy in five centers (Marseilles, Komaki City, Prague, Graz, and Sheffield). A satisfactory follow-up was available for 49 patients (mean follow-up period, 23.66 +/- 13 mo). The mean duration of epilepsy before the GK procedure was 7.5 (+/-9.3) years. The mean frequency of seizures was 6.9/month (+/-14). The mean marginal radiation dose was 19.17 Gy +/- 4.4 (range, 11.25-36). Among the 49 patients, 17 (35%) had a CM located in or involving a highly functional area. RESULTS: At the last follow-up examination, 26 patients (53%) were seizure-free (Engel's Class I), including 24 in Class IA (49%) and 2 patients with occasional auras (Class IB, 4%). A highly significant decrease in the number of seizures was achieved in 10 patients (Class IIB, 20%). The remaining 13 patients (26%) showed little or no improvement. The mediotemporal site was associated with a higher risk of failure. One patient bled during the observation period, and another experienced radiation-induced edema with transient aphasia. Postradiosurgery excision was performed in five patients, and a second radiosurgical treatment was carried out in one patient. CONCLUSION: This series is the first to specifically evaluate the capability of GK surgery to safely and efficiently treat epilepsy associated with CM. Seizure control can be reached when a good electroclinical correlation exists between CM location and epileptogenic zone. Although we do not recommend GK surgery for prevention of bleeding for a CM that has not bled previously, our findings suggest that GK surgery can be proposed for the treatment of epilepsy when the CM is located in a highly functional area.

Familial occurrence of cerebral arteriovenous malformation in sisters: case report and review of the literature.

Cerebral arteriovenous malformations (AVMs) are considered to be congenital disorders. However, their familial occurrence has so far been described in only 19 families in the literature. The authors report on two cases in one family and review the literature. A 45-year-old female subject with sudden onset of headache and vomiting due to a subarachnoid haemorrhage from a small AVM in the posterior part of the corpus callosum near the midline on the left side was studied. Irradiation of the AVM using Leksell's gamma knife led to its complete obliteration. Her older sister presented with temporal seizures at the age of 49 and later also with left hemiparesis, left hemihypaesthesia and dizziness - caused by a large AVM in the right temporal lobe. This AVM was treated by a combination of embolization and irradiation by the Leksell's gamma knife.

Treatment of postherpetic trigeminal neuralgia with the gamma knife.

OBJECT: Postherpetic neuralgia is a syndrome characterized by intractable pain. Treatment of this pain has not yet been successful. Patients with postherpetic neuralgia will therefore benefit from any progress in the treatment strategy. The authors performed gamma knife radiosurgery (GKS) as a noninvasive treatment for postherpetic trigeminal neuralgia (TN) and evaluated the success rate for pain relief. METHODS: Between 1995 and February 1999, six men and 10 women were treated for postherpetic TN; conservative treatment failed in all of them. The median follow up was 33 months (range 8-34 months). The radiation was focused on the root of the trigeminal nerve in the vicinity of the brainstem (maximal dose 70-80 Gy in one fraction, 4-mm collimator). The patients were divided into five groups according to degree of pain relief after treatment. A successful result (excellent, very good, and good) was reached in seven (44%) patients and radiosurgery failed in nine (56%). Pain relief occurred after a median interval of 1 month (range 10 days-6 months). No radiation-related side effects have been observed in these patients. CONCLUSIONS: These results suggest that GKS for postherpetic TN is a relatively successful and safe method that can be used in patients even if they are in poor condition. In case this method fails, other treatment options including other neurosurgical procedures are not excluded.

Initial experience with gamma knife radiosurgery for advanced glaucoma.

OBJECT: The authors assessed the affect of gamma knife radiosurgery on patients with glaucoma. METHODS: Fifteen eyes in 14 patients were treated with gamma knife radiosurgery during a 14-month period. Ocular pain was alleviated in all patients and intraocular pressure was decreased. There were no early side effects. CONCLUSIONS: Further studies are needed to elucidate the best treatment parameters, long-term results, and some of the pathophysiological effects.

Gamma knife radiosurgery of the brain stem cavernomas.

Over 6 years (1992-1998) 26 patients with brain stem cavernomas were treated using the Leksell gamma knife in Prague. 25 patients had a follow up of 6-66, median 24 months. Annual risk of bleeding before radiosurgery was 4%. After gamma knife treatment sudden impairment of neurodeficit reported as rebleeding was observed in 4 patients at 6-51 months, median 16.5 months, after radiosurgery. This represented a 6.8% risk of rebleeding after radiosurgery, which is not significantly different from the risk before radiosurgery. MRI or CT was performed in 24 patients 6-48, median 24, months after radiosurgery. There were no signs of rebleeding in any of the patients, nor any increase of the cavernoma. A decrease of cavernoma size was observed in 8 (33%) of patients. Temporary collateral edema after radiosurgery was detected in 5 (21%) of patients 3-12, median 11, months after radiosurgery. Neurodeficit was observed in 21 of 26 patients before radiosurgery. Improvement of the neurodeficit was detected in 9 (43%) of them 6-36, median 8, months after radiosurgery. Temporary morbidity caused by collateral edema or rebleeding occurred in 7 patients (28%) and permanent morbidity remained in 2 patients (8%). 2 patients died because of rebleeding 6 and 51 months after radiosurgery and the third patient for unrelated reason. Radiosurgery of the brain stem cavernomas was indicated when there was bleeding in the history or progressive neurodeficit and microsurgery was considered too risky. Leksell gamma knife radiosurgery of cavernomas has proved its low morbidity and zero mortality. In case of an insufficient effect of radiosurgery, or if the protective effect from rebleeding comes too late, morbidity and mortality can correspond to the natural course of the disease, as it was left without any treatment.

[Radiosurgical treatment of hypophyseal adenomas with the gamma knife: results in a group of 163 patients during a 5-year period]. / Radiochirurgické lécení adenomu hypofýzy gama nozem: výsledky u souboru 163 nemocných získané v intervalu 5 let.

BACKGROUND: Gamma knife radiosurgery of pituitary adenomas is considered to be very perspective. It can be a very useful complement of traditional microsurgery, pharmacotherapy or fractionated radiotherapy which are seldom a sufficient treatment on their own. The modern radiosurgery does not offer the experience representative enough in this indication. We can offer results of medium long follow-up for tumor growth and hormonal hypersecretion of pituitary adenomas in a relatively large series of patients. METHODS AND RESULTS: We have analyzed a group of 163 patients with pituitary adenoma treated with gamma knife during 5 years and followed 12-60 months, median 24 months after irradiation. An antiproliferative effect has been achieved in 1-2 years using the minimal dose to the margin 16-35 Gy, median 20 Gy in all our patients who were controlled by MRI (n = 126 patients). One half of these adenomas evidently decreased their size. Our effective antiproliferative dose was safe for the surrounding structures. The hormonal normalization has been achieved at 50.4% from 133 hypersecreting adenomas (39/91 = 43% of acromegalics, 11/13 = 85% of patients with Cushing's disease, 2/9 = 22% of patients with Nelson's syndrome, 11/18 = 61% of prolactinomas). The median latency was 12 months. The minimal dose to the margin was 10-45 Gy, median 35 Gy. Rare side effects were provoked only by increasing the dose to influence the hypersecretion-the development of partial hypopituitarism in 3.1% of patients, the panhypopituitarism in 0.6% of patient and there was 1 hemianopic visual field defect (0.6%). CONCLUSIONS: Radiosurgery by gamma knife has a similar value for pituitary adenomas as microsurgery has with different distribution of advantages and drawbacks. This makes it suitable for the combined treatment where pharmacotherapy has its place under special conditions. Fractionated radiotherapy has now a marginal importance.

Gamma Knife radiosurgery of the glomus jugulare tumour - early multicentre experience.

Leksell Gamma Knife was used to treat 66 patients with glomus jugulare tumour at 6 European sites between 1992-1998. The age of the patients ranged between 18-80 years (median 54 years). Gamma Knife radiosurgery was a primary treatment in 30 patients (45. 5%). Open surgery preceded radiosurgery in 24 patients (36.4%), embolisation in 14 patients (21.2%) and fractionated radiotherapy in 5 patients (7.6%). The volume of the tumour ranged 0.5-27 cm(3) (median 5,7 cm(3)). The minimal dose to the tumour margin ranged between 10-30 Gy (median 16.5 Gy). After radiosurgery 52 patients were followed, the follow up period was 3-70 months (median 24 months). Neurological deficit improved in 15 patients (29%) and deteriorated in 3 patients (5,8%), one transient and two persistant. Neuroradiological follow up using MRI or CT was performed in 47 patients 4-70 months (median 24 months) after radiosurgery. Tumour size decreased in 19 patients (40%) while in the remaining 28 patients (60%) no change in the tumour volume was observed. None of the tumours increased in volume during the observation period. Control angiography was performed in 6 patients. Pathological vascularisation completely disappeared in one patient, reduced in two and there was no change in the remaining three. Radiosurgery proves to be a safe treatment for glomus jugulare tumour with no mortality and no acute morbidity. Because of its naturally slow growth rate, up to 10 years of follow up will be necessary to establish a cure rate after radiosurgery for these lesions.

Gamma knife radiosurgery of meningiomas in the cavernous sinus region.

For 6 years (1992-1998) we have treated 67 patients with cavernous sinus meningioma using the Leksell gamma knife in the Hospital Na Homolce, Prague. The age of the patients ranged between 19-82 years, median 57 years. Radiosurgery was the primary treatment in 64.2% of the patients, in the rest a microsurgical resection preceded. The volume of the tumour ranged from 0.9-31.4 cm3, median 7.8 cm3. The meningioma was distant from the optic tract in 58% of the cases, in 12% of the cases there was a contact with the tumour and the optic tract without its compression and in 30% of the cases there was a compression of the optic tract caused by the meningioma. The dose to the tumour margin ranged from 10-14 Gy, median 12 Gy. The follow up was available in 53 patients, in intervals of 2-60 months, median 19 months. There was no change in the tumour volume in 48% of the cases, in 52% of the cases a decrease of the tumour volume occurred. No increase of the tumour volume was observed. Clinical symptoms and signs improved in 35.8% of the patients, temporary morbidity was 3.8%. The mortality of the treatment was zero. Hitherto, the results of gamma knife radiosurgery of cavernous sinus meningioma have proved its safety and efficiency, although long term experience with a large group of patients is missing. Advances in neuroradiology and radiosurgical technique have allowed us to treat tumours with a closer contact to the optic tract and nerves compared with the past.

[The first year of use of the Leksell gamma knife at the Hospital Na Homolce--results after 5 years]. / První rok provozu Leksellova gama noze v Nemocnici na Homolce--5 let poté.

The first Leksell gamma knife procedure was performed in Prague on 26th October 1992 and during the first year 156 patients were treated at the department of stereotactic and radiation neurosurgery. 42% patients suffered from a vascular lesion, 39% of patients from a benign tumour and 19% patients from a malignant tumour. Radiosurgery using the gamma knife is a non-invasive stereotactic neurosurgical procedure. Radiosurgery, as microsurgery, must be evaluated not only early, but also the late effect after the treatment some years. Evaluation of the results is therefore an ongoing process and results of the first year with the 5-year follow up are presented. At this time radiosurgery has a zero treatment mortality and the present morbidity with regard to the diagnosis 0-10%.

Gamma Knife radiosurgery for epilepsy associated with cavernous hemangiomas: a retrospective study of 49 cases.

A retrospective multicenter study was performed to evaluate the effectiveness of Gamma Knife radiosurgery (GKRS) in the treatment of drug resistant epilepsy associated with cavernous hemangiomas (CH). The mean duration of epilepsy before GKRS was 7.5 ¿ 9.3 years. The mean frequency of seizures was 6.9 ¿ 14/month. The mean marginal dose was 19.2 ¿ 4.4 Gy (range 11.3 to 36 Gy). The mean follow up was 23.7 ¿ 13 months. At the most recent follow-up examination, 26 (53%) patients were seizure-free (Engel s class I) including 24 in class IA (49%) and two (4%) patients with occasional auras (class IB, 4%). A highly significant decrease in the number of seizures was achieved in 10 (20%) patients, which is class lIB. The remaining 13 (2.6%) patients showed little or no improvement. A medial temporal location was associated with a higher risk of failure. In contrast, all patients with central region CH were seizure free. Two severe but transient complications were observed. There was hemorrhage in one patient and another patient suffered from radio-induced edema with transient aphasia. This series is the first demonstrating that GKRS can be used safely and efficiently to treat epilepsy associated to CH. Seizure control can be reached when a good electro-clinical correlation exists between CH location and epileptogenic zone. Our findings suggest that GKRS can be used to treat epilepsy for CH located in highly functional areas, particularly the central region.

The role of Gamma Knife radiosurgery in arteriovenous malformation with aneurysms.

A review of 217 patients treated with Gamma knife radiosurgery (GKRS), at Hospital Na Homolce, Prague, between October 1992 and January 1998 for arteriovenous malformation (AVM) is presented. Forty-one patients (18.9%) with an AVM and associated aneurysm are the subjects of special interest for this study. The nidus volume in the presence of an aneurysm lying close to the nidus or within it was significantly larger than the nidus volume in cases where the AVMs had no associated aneurysm, suggesting that an increased flow in a larger AVM may be an important factor for aneurysm formation. The association of an arterial aneurysm with an AVM significantly increased the chance of hemorrhage when compared to the group with AVM and no aneurysm. Ten patients out of 14, who had an aneurysm close to or within the nidus, showed a complete obliteration of their AVM and aneurysm, although the latter was not always included within the irradiated volume. Thus, this study indicates that radiosurgery alone could be the method of choice for the treatment of a combination of AVM and aneurysm, if the aneurysm is close to or within the nidus.

Leksell gamma knife radiosurgery of the tumor glomus jugulare and tympanicum.

We have treated 14 patients with glomus tumor during the 4 years (of 1993 to 1997) using Leksell Gamma Knife radiosurgery. The male: female ratio was 1:3.7, and the mean age 48.6 years (range 22-75 years). The mean tumor volume was 5.5 cm3 (range 0.7-11.3 cm3). The mean maximum dose was 37.4 Gy (range 20-44 Gy). The mean margin dose was 19.4 Gy (range 10-25 Gy). In 3 patients, infrabasal spread of the tumor could not be delineated on peroperative stereotactic CT scans. As a result, this portion of the tumor was treated in 2 patients at a second stage using stereotactic MRI. Follow-up in 11 patients ranged from 6 to 42 months (mean 20.5 months). Hearing on the affected side was further impaired in 3 patients. Tinnitus, vertigo and ataxia improved in 3 patients, headache and nausea in 2 patients. Angiography after radiosurgery was performed in 3 patients. In one patient 12 months after the radiosurgery, pathological vascularisation had completely disappeared. In another patient pathological vascularisation was still present 22 months after the first stage, despite two-stage radiosurgery, although the tumor volume decreased 30%. In the last patient, vascularisation and tumor volume partially decreased 12 months after radiosurgery. The volume of the tumor decreased in 4 patients. No change in tumor volume has been observed in any of the other patients to date. Radiosurgery proves to be a safe treatment for glomus tumor with no acute morbidity. Because of its naturally slow growth rate, up to 10 years follow-up will probably be necessary to establish the therapeutic effectiveness of radiosurgery for glomus tumor.

Gamma knife treatment of trigeminal neuralgia: clinical and electrophysiological study.

Between October 1995 and October 1996, we treated 49 patients suffering from trigeminal neuralgia with Gamma Knife radiosurgery. There were 23 males and 26 females. The mean age was 68 (range 38-94 years) The root of the trigeminal nerve close to brain stem was chosen as the target. The maximum dose was 70 Gy in 24 cases and 80 Gy in 25 cases. A single shot with the 4-mm collimator was used. 13 patients underwent Gamma Knife treatment of trigeminal nerve root without any previous surgical procedures. 31 patients suffered from an essential neuralgia (EN), while 7 had neuralgia related to multiple sclerosis (MS). Three had atypical neuralgia (AN) and 8 patients had postherpetic neuralgia (PN). Patients were divided into five groups according to pain reduction. The success rate of pain relief (excellent, very good and good responses) in these patients was: EN 77% of patients, MS 43%, AN 33% and PN 38% of patients. Pain relief occurred after latent intervals of between 1 day and 8 months (median 2 months and mean 2.8 months). Clinically detected complications after radiosurgery occurred only in the form of tactile hypesthesia in 6%. In a selected group of 18 patients, we observed slight electrophysiological changes in 2 patients (11%) after Gamma Knife treatment.

[Personal experience with treatment of vascular diseases using the Leksell gamma knife]. / Nase zkusenosti s lécbou nekterých cévních afekcí Leksellovým gama nozem.

The application of radiosurgical treatment in ophthalmology is a new and not quite common procedure. The existence of 80 departments in the world with more than 15,000 treated patients suggests however that the therapeutic method is being extended and that its application in ophthalmology will be more extensive in future. The most numerous indication groups for treatment with a Leksell gamma-knife(LGK) worldwide are vascular malformations (44%), benign tumours (33%) and malignant tumours (22%). Other groups include among others functional disorders and metastatic processes (15).

[2 years' experience with treatment of uveal melanoma using the Leksell gamma knife]. / Dva roky zkuseností s lécbou uveálního melanomu Leksellovým gama nozem.

In the last years, the therapy of ocular melanoma with Leksell's gamma-knife was indicated at several clinics in Prague. It referred to bulky tumors and to unfavourably localized tumors so that only enucleation of the eyeball was the only alternative in our conditions. The results of the treatment of 11 patients have been evaluated in this article. Some other patients treated with this method have not been included in this sample for various reasons (short-term follow-up, combination of radiotherapy with gamma-knife with other therapeutic modality etc.) Gradual decrease in tumor size developed in 10 patients during follow-up. The decrease in tumor size has been observed on repeated ultrasound examinations and magnetic resonance imaging. The growth of tumor was reappeared in one patient, which led to the necessity of enucleation of the eyeball. The complications in other patients were numerous but not serious to such extent that would lead to enucleation. Marked deterioration in visual acuity connected with the treatment occurred in 6 patients. The results achieved by this method are comparable with those achieved by other therapeutic modalities and with the results from other clinics employing gamma-knife for the treatment of uveal melanoma. The results lead to the conclusion that this is an effective method of treatment of uveal melanoma and that this method is able to go through further development, especially in combination with other therapeutic modalities.

[Radiosurgical hypophysectomy in painful bone metastases of breast carcinoma]. / Radiochirurgická hypofyzektomie u bolestivých kostních metastáz karcinomu prsu.

Radiosurgical hypophysectomy using Leksell gamma knife was performed to the patient with cancer pain from bone metastases of the breast cancer, relief of the pain was achieved. Patient survived 26 months after hypophysectomy. Review of the literature concerning relief of the pain after hypophysectomy is presented.

"Epileptosis"--a syndrome or useless speculation?

102 patients were divided into 3 groups: epileptics, psychotics and epileptics with psychotic symptoms. All had long been monitored for a number of clinical and laboratory parameters. Though different in many respects, all share states of sudden dysphoria, cacophoria, panic anxiety, horror, and EEG (stereo-EEG, too) signs of epileptic or other gross anomalies, often correlated to those affective disorders. Attacks of dysphoria, epilepsy, and psychosis come spontaneously and in response to biological (hypoglycemia, sleep deprivation, alcohol, menses) or psychosocial stimulation (agitation, quarrels, fear of redundancy, psychic trauma). These states (attacks, dysphoria, "neurotic" or even psychotic episodes) often provoke one another. -Calling this syndrome epileptosis, we believe its mechanism is due to lesions of the limbic and brainstem modulation systems. At the start of the process there is an epileptic focus in the amygdalo-hippocampal complex (AHC) which in itself can trigger simple or complex partial paroxysm but also-by means of electric stimulation of the AHC-states of dysphoria, anxiety, and psychotic hallucinations. Besides, a form of pathological learning develops in premorbid "hypersensitive" personality which can be put down to associative learning and to Overton's phenomenon of "state-dependent retention of learned responses". This may give rise to mutual stimulation where epileptic focal activity in AHC can provoke dysphoria while an external psychosocial situation can trigger epileptic activity there, too (AHC). Since there need not always be mydriasis (though other vegetative signs such as tachycardia, tachypnoea, nausea, blush and others are frequent) or unconsciousness, and some psychomotor manifestations may be out of the ordinary, and scalp EEG may be normal, such patients are often regarded as "hysterics" or malingerers.