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between radiology and pathology departments with busyschedules. Contrast studies are best performed underfluoroscopic control, with a videotape running, to avoidintroduction of excessive contrast material that may obscurethe anatomy. A choanagram on a 17-week fetus, for

example, requires only a few millilitres.This joint approach to the necropsy seems to be a natural

development from the team approach to the management ofintrauterine abnormality. The more that members of thedysmorphology team learn from each other, the more theycan reduce the uncertainty in counselling that bedevilsantenatal diagnostic work and improve the quality of boththe perinatal necropsy and antenatal sonography. It may bethis continuous interaction between colleagues that keepsthe perinatal necropsy rate at around 85 % in many centreslOwhere the adult necropsy is declining.

PSEUDOSTATUS EPILEPTICUS

STATUS epilepticus is fortunately an uncommon

complication of epilepsy1. Recent clinical and

electroencephalographic (EEG) studies have shown thatmany patients who present with apparent status epilepticusin fact have "pseudostatus epilepticus"2 A-a conditionmimicking status epilepticus (at least superficially), but inwhich the repeated seizures are psychogenic (synonyms:hysterical seizures, simulated seizures, pseudoseizures,non-organic seizures). Its true prevalence is uncertain, butin specialised neurological practice pseudostatus iscommoner than true status; and the frequency andimportance of this condition are insufficiently recognised innon-specialist practice.3

Correct diagnosis is crucial since the hazards of thecondition arise from treatment undertaken in the mistakenbelief that the patient has true status epilepticus. To theexperienced observer, the apparent seizures are seldomconvincing 4°5 They may not have the classic features ofconvulsive seizures: there is often vocalisation and bizarrebehaviour, and preservation of consciousness is usually easyto demonstrate despite the apparent convulsions.

Incontinence, tongue biting, and cyanosis may occur but areless common than in true status epilepticus.3 The medicalhistory is very important in diagnosis. Inquiry usuallyreveals a long history of personality disorder, often withhysterical features (eg, non-organic paralysis6) and suicidalgestures.7,8 The epilepsy history is usually highly atypical,with an unusual pattern, odd responses to treatment, andnormal (or nonspecifically abnormal) EEG recordings; andin the records one can often find earlier pseudoseizures orpseudostatus. The patients are usually, but not always,female.9 Pseudoseizures and pseudostatus may occur in

10. Chan A. Maternal Mortality Committee: annual report relating to perinatal deaths.1987-1988. Adelaide: South Australian Health Commission.

1. Delgado Escueta AV, ed. Status epilepticus. Advances in neurology, vol 34. NewYork: Raven, 1983.

2. Toone BK, Roberts J. Status epilepticus: an uncommon hysterical conversionsyndrome. J Nerv Ment Dis 1979; 167: 548-52.

3. Howell SJ, Owen L, Chadwick DW. Pseudostatus epilepticus. Quart J Med 1989; 266:507-19.

4. King DW, Gallagher BB, Murvin AJ, et al. Pseudoseizures: diagnostic evaluation.Neurology 1982; 32: 18-23.

5. Oxley J, Roberts M. The role of prolonged ambulatory monitoring in the diagnosis ofnonepileptic fits in a population of patients with epilepsy. In: Stott RD, Raftery EB,Goulding L, eds. ISLAM 1981. Proceedings of the 4th International Symposiumon Ambulatory Monitoring. London: Academic Press, 1988: 195-202.

6. Sonnen AEH. Psychogenic seizures. Br J Clin Pract 1981; 18 (suppl): 53-57.7. Roy A. Hysterical fits previously diagnosed as epilepsy. Psychol Med 1977; 7: 271-73.8. Gross M. Pseudoepilepsy: a study in adolescent hysteria. Am J Psychiatry 1979; 136:

210-13.9. Lesser RP. Psychogenic seizures. In: Pedley TA, Meldrum BS, eds. Recent advances

in epilepsy, vol 2. Edinburgh: Churchill Livingstone, 1985: 273-96.

patients who also have true epileptic seizures, and this maycomplicate the clinical picture.3,10,11 The burden of diagnosisusually falls on the hapless casualty officer or the generalmedical team on call, and it is at this level that most of themisdiagnoses are made; the importance of a good history andprecise clinical observation cannot be exaggerated. Electro-encephalography during the episode is of the greatest valueand may permit a definitive diagnosis. In pseudostatus, theEEG may show minor abnormalities or signs of medication,but there will be neither ongoing epileptic activity nortypical postictal changes.3 In true status epilepticus, theEEG changes of epilepsy are usually very obvious.

Misdiagnosis leads to mistreatment, usually withintravenous anticonvulsants (especially the benzo-

diazepines). These curtail the seizures only afterconsciousness has been abolished; as the patient recoversconsciousness the seizures recur, and more medication isadministered. Intensive care then may become necessary,and it is not unusual for such patients to be paralysed andventilated before the correct diagnosis is suspected. Thisclearly carries a severe risk to the individual as well as being adrain on time and resources. Indeed, the more dramatic thepresentation, the more likely is the status epilepticus to bepsychogenic; a recent patient was flown by his healthauthority to a distant hospital by helicopter. One reportedpatient has had 80 emergency admissions to nine differenthospitals in three regions, 21 episodes diagnosed and treatedas status, and she was admitted to an intensive therapy uniton 5 occasions.3What are the psychological reasons for this behaviour,

which carries such disapprobation and risk? Some patientsseem to malinger, some are psychopathic in disposition,12,13few have a formal psychiatric diagnosis other than

personality disorder, and in some the seizures occur simplyin the context of unhappiness or loneliness, denial, or as a"cry for help". Pseudoseizures are a frequent manifestationof hysterical conversion; in Ljungberg’s study14 of 381hysterics, 38% had seizures as part of the illness, these beingthe major feature in 20%. Psychiatric treatment must takeaccount of this varying causation; it is usually behaviourallydirected,9 and must include vigorous attempts to preventrecurrence of this dangerous behaviour.

COMPARTMENT SYNDROME OF THE THIGH

IN 1941, Bywaters and BealP reported on the crushedlimbs of civilian victims of London’s wartime air raids.When massive limb swelling, ischaemic muscle necrosis,myoglobinuria, and renal failure complicated such injuriesthey recognised it as a clinical entity-crush syndrome. Thecause of such massive muscle damage was often raisedpressure within one or many compartments of the arm or

leg. Mubarak et al2 defined a compartment syndrome as an

10. Gumnit RJ. Behavioural disorders related to epilepsy. Electroenceph Clin Neurophysiol1985; 37 (suppl): 313-23.

11. Lesser RP, Lueders H, Dinner DS. Evidence for epilepsy is rare in patients withpsychogenic seizures. Neurology 1983; 33: 502-04.

12. Holmes GL, Sackeralles JC, MeKiernan J, Ragland M, Driefuss FE. Evaluation ofchildhood pseudoseizures using EEG telemetry and video monitoring. J Pediatr1980; 97: 554-58.

13. Wilkus RJ, Dodrill CB, Thompson PM. EEG monitoring and psychological studies ofpatients with pseudoepileptic seizures. Epilepsia 1984; 25: 100-07.

14. Ljungberg L. Hysteria: a clinical prognostic and genetic study. Acta Psychiatr NeurolScand 1957; 112 (suppl): 1-162.

1. Bywaters EGL, Beall D. Crush injuries with impairment of renal function. Br Med J1941; i: 427.

2. Mubarak SJ, Hargens AR, Owen CA, Garetto LP, Akeson WH. The wick cathetertechnique for measurement of intramuscular pressure. A new research and clinicaltool. J Bone Joint Surg 1976; 58A: 1016-20.

486

increase of the interstitial pressure in a closed osseofascial

compartment that leads to microvascular compromise. Thesyndrome is well recognised in the forearm and leg but is lesscommon in the thigh and upper arm. Nonetheless, Schwartzet al3 lately reported the syndrome in twenty-one thighs ofseventeen patients.There are three main osseofascial compartments of the

thigh-lateral, posterior, and medial adductor. The psoasmay be considered an additional compartment and is itselfvulnerable to the compartment syndrome.4 The majorcompartment syndromes may be confined to one

compartment or shared by many. Many factors maycontribute to the rise in pressure that provokes the

syndrome. Whilst external compression may be caused byfalling masonry, for example, the weight of the leg alone, ifheld in an extreme position, may compromise venous returnand provoke a rise in interstitial pressure. Thus the

syndrome is seen as a complication of drug abuse.7.s It is alsoseen in patients with multiple injuries, in whom systemichypotension and late coagulopathy may further compromisethe compartment at risk. Severe vascular injury with aortic,iliac, or femoral thrombosis or laceration increases the riskseven more. Femoral fracture, either treated or untreated,may cause bleeding within closed compartments.9 Therehas been an increasing number of reports of militaryanti-shock inflatable trousers contributing to the

syndrome.10,11 Tourniquets by themselves, if applied tootightly or for too long, have also been implicated.

In conscious cooperative patients the syndrome is notdifficult to recognise clinically. A swollen, tense thigh withdisproportionate pain and often with paraesthesiae in thedistribution of the nerve traversing the trappedcompartment is typical. The pain is usually aggravated bystretching the muscles contained in the compromisedcompartment. Diagnosis is more difficult in unconsciouspatients with multiple injuries: an even more rigorous watchshould be kept for increased swelling of any compartmentand, if necessary, compartment pressures should bemeasured. Where complex techniques are not available, asimple wide-bored needle with a loop of saline may be used,as described by Whitesides et al.12,13 Simple hand-helddevices allow repetitive sampling of pressures to beundertaken easily. Each compartment needs to bemeasured. If the existence of a compartment syndrome isconfirmed, decompressive fasciotomy should be done assoon as the general state of the patient makes it feasible. Theanterior and posterior compartments of the thigh may most

3. Schwartz JT, Brumback RJ, Lakatos R, Polka A, Bathon GH, Burgess AR. Acutecompartment syndrome of the thigh. J Bone Joint Surg 1989; 71A: 392-400.

4. Al-Zamil. Psoas muscle hematoma: an acute compartment syndrome. VASA 1988;17: 141-43.

5. Clancy GJ. Acute posterior compartment syndrome in the thigh. J Bone Joint Surg1985; 67A: 1278-80.

6. German PW, McAndrew MP. Acute antenor compartmental syndrome of the thighfollowing contusion. J Orthop Trauma 1987; 1: 68-70.

7. Schreiber SN, Liebowitz MR, Bernstein LH, Srinivasan K. Limb compression andrenal impairment complicating narcotic overdose. N Engl J Med 1971; 284: 368.

8. Dolich BH, Aiache AE. Drug-induced coma: a cause of the crush syndrome andischemic contracture. J Trauma 1973; 13: 223.

9. Tarlow SD, Achterman CA, Hayhurst J, Avadia DN. Acute compartment syndromein the thigh complicating fracture of the femur. A report of three cases. J Bow JointSurg 1986; 68A: 1439-43.

10. Bass RR. Thigh compartment syndrome without lower extremity trauma followingapplication of pneumatic antishock trousers. Ann Emerg Med 1983; 12: 382-84.

11. Templeman D. Lower extremity compartment syndromes associated with use ofpneumatic antishock garments. J Trauma 1987; 27: 79-81.

12. Whitesides TE, Harada K, Morimoto K. Compartment syndromes and the role offasciotomy. its parameters and techniques. In: Instructional course lectures, vol 26.American Academy of Orthopedic Surgeons. St Louis: Mosby, 1977: 179-96.

13. Whitesides TE, Haney TC, Monmoto K, Harada K. Tissue pressure measurementsas a determinant for the need of a fasciotomy. Clin Orthop 1975; 113: 54-51.

easily be decompressed through a long, lateral thighincision;9 this approach allows release of the very tough,thick lateral intermuscular septum together with the thinnerposterior intermuscular septum. Pressure in the medialcompartment should then be measured separately: if it is stillhigh, a separate medial incision should be carried out torelease the median, adductor compartment.

If the operation is done too late, necrotic muscle will needexcision. The wound should not be closed primarily;secondary suture or skin grafting is necessary. Other

compartment syndromes of the same or other limbs mayneed simultaneous decompression. If possible, fracturesshould be stabilised to minimise the shock reaction. When a

single compartment is affected, prompt diagnosis anddecompression often lead to a very satisfactory outcome,with full restoration of function. In patients with multipleinjuries, mortality and morbidity remain high. In the seriesof Schwartz et al, eight of the seventeen patients with thighcompartment syndrome died and infection developed at thefasciotomy site in six of the other nine. Motor weakness andsensory deficit were common in the survivors.

VITAMINS AND THE NEURAL TUBE

On p 498 we record the latest findings from ProfessorSmithells and his colleagues in Leeds on the Yorkshire armof a study on vitamin supplementation to prevent recurrenceof neural tube defects .(NTD). Their earlier multicentreefforts, ethical approval for a controlled trial having beenrefused, had been charged with possible selection bias,hence the defined population approach used in this week’sletter. An NTD recurred in only 1 of 150 fullysupplemented mothers but in 18 (5-6%) of 320

unsupplemented mothers. Furthermore, as more and more.women opted for supplementation over the years therecurrence-rate did not increase in the unsupplemented-asit might be expected to have done had there been a selectionbias.

In the United States NTDs are less common than theyare in Britain, and recurrence rates are lower too. Relativeimmunity from these congenital defects has not protectedthat country from the vitamin controversy, however. Lastweek saw the appearance of a case-control study fromCalifornia and Illinois.1 Within five months of delivery or ofdiagnosis of an abnormality 571 women with a completedNTD-affected pregnancy (first or recurrent) were

interviewed, together with 546 control mothers with otherseriously adverse pregnancy outcomes and 573 normalcontrols. Whether the analysis related to vitamin tabletsalone or to tablets and fortified cereals the odds ratios

provide no support for the view that supplementationprotects against NTD. An earlier interview-based studyfrom the United States2 had pointed in the oppositedirection, in favour of a protective role for vitamins, butrecall bias (interviews took place at least 2 z years afterdelivery) is a possibility, if one predicates that women withan affected pregnancy assume, years later, that they couldnot have taken a supplement. Meantime the UK MedicalResearch Council trial continues, with a birth planned foraround 1992.

1. Mills JL, Rhoads GG, Simpson JL, et al. The absence of a relation between thepreconceptional use of vitamins and neural-tube defects. N Engl J Med 1989; 321:430-35.

2. Mulinare J, Cordero JF, Erickson JD, Berry RJ. Periconceptional use of multivitaminsand the occurrence of neural tube defects. JAMA 1988; 260: 3141-45.