EUROPEAN JOURNAL OF EMERGENCY MEDICINE, 2000, 7, 291-293 Transient global amnesia or subarachnoid haemorrhage? Clinical and laboratory findings in a particular type of acute global amnesia V. MONZANI", A. ROVELLINI', G. SCHINCO! and V. SILANI? Division of Emergency Medicine, Department of Internal Medicine and “Institute of Neurology, University of Milan, IRCCS Ospedale Maggiore di Milano, via Francesco Sforza 35, 20122 Milan, Italy Acute global amnesia may be due to several causes, such as transient global amnesia (TGA), acute drug-related confusional state, toxic substances, metabolic abnormalities, infective dis- eases, cerebral tumours, cerebrovascular accidents, subarachnoid haemorrhage and epilepsy. In particular both TGA and subarachnoid haemorrhage may be precipitated by sexual activity; by contrast the two diseases are quite different in prognosis and treatment. Ten subjects were admitted in the period 1997-99 to our emergency department for acute global amnesia related to sexual activity. They represented 18% of total acute global amnesias observed in the same period. All patients were males, aged between 41 and 64 years. TGA was found in nine cases, while one patient had subarachnoid haemorrhage. due to rupture of an aneurysm of the right middle cerebral artery. The patient with subarachnoid haemorrhage showed neurologic defects (second-degree nystagmus and retropulsion), while no major neurologic abnormalities were found in TGA. Likewise computerized tomography (CT) scan was positive only in the case of subarachnoid haemorrhage. Patients and relatives in most cases left out sexual activity os a trigger factor, This experience indicates that acute global amnesia related to sexual activity is mostly due to TGA. Major neurologic signs are suggestive of subarachnoid haemorrhage and an immediate CT scan is recommended. Targeted questions are needed to identify the cause of the event © 2000 Lippincott Williams & Wilkins, Keywords: acute global amnesia; transient global amnesia; subarachnoid haemorrhage INTRODUCTION activity has in particular to be discriminated from subarachnoid haemorrhage, which sometimes Acute global amnesia is an uncommon syn- presents as an acute amnesia and which may be drome. which may be due to several causes, such triggered by sexual excitement." 45 transient global amnesia (TGA), acute drug related confusional state, toxic substances, CASE REPORTS metabolic abnormalities, infective diseases, cere- bral tumours, cerebrovascular accidents, sub- : Ten subjects were admitted in the period 1997-99 arachnoid haemorrhage and epilepsy.’ Among to the Emergency Department of the IRCCS Os- these TGA is one of the most benign syndromes, pedale Maggiore in Milan for acute global amne defined by the acute global loss of memory, sias related to sexual activity. They represented preservation of consciousness, behavioural 18% of total acute global amnesia observed in the changes, repetitive questioning and lack of focal same period neurologic defects.” Frequently no cause can be determined. TGA occasionally follows emotional Patients’ clinical characteristics are summari stimuli, physical exertion, sharp pain or haemo- in the Table 1. All patients were healthy males, dynamic alterations aged between 41 and 65 years (mean age + SEM 55 + 3 years). As shown, blood pressure ranged Even sexual activity may induce TGA, often as from low to high values, No alterations were sociated with a headache.’ TGA related to sexual found in blood examinations, Amnesia was most frequently associated with confusion and repeti tive questioning. Headache was present in 40% of 1 f “To wham correspondence should be addressed cases © 2000 Lippincott Williams & Wilkins 22 Table 1. Patients’ clinical characteristics MONZANI, ROVELLINI, SCHINCO and SILANI Case Age Sex Blood Headache Symptoms Neurologic CT scan pressure besides amnesia signs AR. 64 M 140/85 Yes Repetitive questioning None Normal GT, 62 M 170/110 No Repetitive None Age compatible questioning V.M. 41 M 150/85 Yes None None Normal MF. 65 M 100/60 No Confusion None Age compatible GB. 52 M 180/105 No Repetitive None Normal questioning aid 45 M 140/80 Yes None None Normal GF 60 M 160/80 Yes Repetitive None Normal questioning E.B. 49 M 130/75 No Repetitive None Normal questioning RC. 51 M 140/80 No Confusion None Normal AP. 63 M 150/90 No Repetitive Left beating Intracranial questioning nystagmus haemorrhage plus retropulsion Neurologic abnormalities were found only in one case, In fact the patient with subarachnoid hae- morrhage presented a second-degree left-beating nystagmus and retropulsion at the Romberg manoeuvre. Likewise, computerized tomography (CT) scan showed pathological findings only in the case of subarachnoid haemorrhage. Patients and relatives in most cases left out sexual activity as a trigger factor. DISCUSSION The clinical characteristics of TGA have been described by several studies.**”~"’ Miller et al.? found that the syndrome occurs most frequently after the age of 50. Hodges et al,’ suggested a clinical classification, distinguishing pure TGA (attacks with no neurologic signs and of more than 1 hour in duration, which do not require detailed investigations) from probable epileptic amnesia (attacks of less than an hour or rapidly recurrent) and from probable transient ischaemic amnesia (a minority of cases with additional focal neurologic defects during the attack). Other au- thors however believe the presence of neurologic defects to be compatible with the diagnosis of TGA.’ Particular antecedent events and activity such as exertion were demonstrated in one-third of the subjects with TGA by Miller et al. TGA related to sexual activity is a particular type of transient global amnesia."° '* Although few data are available in the literature, this syndrome is more frequently described in males. In agree- ment with this finding, all subjects observed in our report were middle-aged men. Almost half of our patients showed headache, EUROPEAN JOURNAL OF EMERGENCY MEDICINE (2000) 7(4) though no one had a clinical history of migraine. This is in keeping with previous studies demon- strating that TGA is often associated with a headache."* Headache appeared to be signifi- cantly more common in patients with TGA than in patients with transient cerebral ischaemic dis- ease or in normal subjects in a study by Hodges and Warlow.' It is known that the diagnosis of acute global amnesia related to sexual activity is often un- recognized. That is mainly due to the reserve of patients and relatives. In our report, targeted questions were needed to find out the triggering events of the syndrome. The duration of amnesia has been proposed as one of the diagnostic criteria of TGA.’ The pre- sent experience does not agree with this state- ment and suggests the need for early exclusion of brain haemorrhage. The lack of focal neurologic defects is considered to be one of the main criteria for TGA, as pro- posed by Caplan and by Hodges.” These authors have however demonstrated that minor abnor- malities such as mild brain stem symptoms do not exclude the diagnosis. On the contrary, the finding of nystagmus and retropulsion in our patient with subarachnoid haemorrhage raised the suspicion of a more severe disease. The relationship between sex and subarachnoid haemorrhage is known but still under discussion. In fact, sexual intercourse was the precipitating factor in six out of 50 cases of subarachnoid haemorrhage as reported by Lundberg and Os- terman.® Conversely, Wardlaw and White did ACUTE GLOBAL AMNESIA not include sexual activity among hazardous fac- tors."° Subarachnoid haemorrhage, however, in- frequently presents as an acute global amnesia. The involvement of the thalamus is sometimes responsible for the syndrome,"* probably due to an interference of the mamillothalamic tract, ven- troamygdalofugal pathway or dorsal noradrener- gic bundle. In other cases the temporary hippocampal dysfunction related to the haemor- rhage may explain the occurrence of amnesia.'”"* The question, whether CT scan is a necessary procedure in the emergency department in order to diagnose TGA is not as yet defined.’ In our series CT scan showed pathological results only in the patient with subarachnoid haemorrhage. 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