<<

J Neurol Neurosurg Psychiatry: first published as 10.1136/jnnp.37.7.802 on 1 July 1974. Downloaded from

Journal ofNeurology, Neurosurgery, and Psychiatry, 1974, 37, 802-810

Abnormalities of and smell after head trauma

PAUL J. SCHECHTER AND ROBERT I. HENKIN'

From the Section on Neuroendocrinology, National Heart and Lung Institute, - National Institutes of Health, Bethesda, Maryland 20014, U.S.A.

SYNOPSIS Abnormalities of taste and smell were studied in 29 patients after head trauma. These abnormalities included decreased taste acuity (), a distortion of taste acuity (), decreased smell acuity (), and a distortion of smell acuity (). This syndrome can occur even after minimal head trauma and can begin months after the moment of injury. The patients exhibited a significant decrease in total serum concentration (patients, 77 + 3 Vg/100 ml, mean + 1 SEM, vs controls, 99 + 2 jg/100 ml, P> 0-001) and a significant increase in total serum copper concentrations (113 + 4 Cug/100 ml vs 100 + 2 [ug/100 ml, P <0-001) compared with control subjects. Symptoms of hypogeusia, dysgeusia, and dysosmia are frequent sequelae of and are important to the patients and to their care after trauma. Protected by copyright. Loss of olfactory acuity after trauma to the head disturbances (Mifka, 1965). Usually decreased is a well-recognized phenomenon and has been taste acuity has been reported to be accom- estimated to occur in 1.3% to 65% of all head panied by decreased olfactory acuity. In the injuries (Laemmle, 1931; Sumner, 1964). Blows majority of cases return of taste acuity has been to the occiput have been reported as more likely reported in the course of time, suggesting that to produce loss ofsmell, presumably by a contre- this abnormality is more amenable to correction coup effect, than blows to the or other than post-traumatic smell loss (Sumner, 1967). sites on the head (Sumner, 1964) and even trivial No relationship between severity of head injury injuries have been shown to result in olfactory and the occurrence or duration of taste loss has sensory deficits (Sumner, 1964). In addition, been previously reported (Sumner, 1967). distortion of odours has been described after Distorted taste sensations have been reported head trauma (Leigh, 1943; Sumner, 1964, 1967). to accompany post-traumatic taste loss (Sumner,

Spontaneous recovery of olfactory acuity has 1967). The incidence of distortion of either taste http://jnnp.bmj.com/ been claimed in 8% to 3900 of patients suffering or smell or both in patients with post-traumatic from post-traumatic loss of smell (Leigh, 1943; taste loss has been estimated to be between 6% Sumner, 1964). and 33%o (Leigh, 1943; Sumner, 1964, 1967). On the other hand, abnormalities of taste However, the presumed diagnosis of 'anos- sensation after head injury have received much mia' or '' has been made in these studies less attention and have been reported to occur on the basis ofclinical subjective reports, without less frequently than do olfactory disorders. The quantitative measurements to specify the degree first description of taste loss after head trauma or extent of the taste or smell losses. on September 23, 2021 by guest. was made by Ogle in 1870. Since that time, addi- In this paper we present data on 29 patients tional cases of post-traumatic taste loss have who experienced abnormalities of taste and been described in the literature. The incidence of smell after head trauma. Quantitative estimates this condition has been estimated to be approxi- of the losses of taste and smell were made. The mately 0-40/o of all head injuries, a much lower relationship ofthe sensory losses to alterations in incidence than that for post-traumatic olfactory trace metal metabolism will be discussed. I Address for correspondence: Dr Robert I. Henkin, Section on Neuroendocrinology, Experimental Therapeutics Branch, National METHODS Heart and Lung Institute, Bldg 10, Room 7N262, Bethesda, Maryland 20014, U.S.A. On the bases of careful evaluation of symptoms of 802 J Neurol Neurosurg Psychiatry: first published as 10.1136/jnnp.37.7.802 on 1 July 1974. Downloaded from

Taste and smell changes after head trauma 803 approximately 400 patients with taste and smell com- Intermittent or persistent odour, plaints we have described alterations in taste and pleasant or unpleasant, perceived when no apparent smell as follows (Henkin, 1971): odorant is present. ABNORMALITIES OF TASTE Hypogeusia Decreased to taste sweet, sour bitter tastants. Heterosmia Inappropriate smell of consistent ability salt, and/or nature associated with odorants. This smell is Ageusia Inability to detect or recognize any tastant unusual and unexpected but not necessarily foul or (operationally defined as inability to detect or recog- obnoxious. nize saturated solutions of NaCl or , 500 mM HCI, or 8 M urea). MEASUREMENT OF TASTE AND SMELL ACUITY Taste acuity was measured by determining detection and Dysgeusia General description of any distortion of recognition thresholds for representatives of the salt, normal taste perception. sweet, sour, and bitter taste qualities by a forced- choice, three-stimulus drop technique (Henkin et al., Cacogeusia Abhorrent, obnoxious taste produced 1963; Henkin et al., 1971). chloride was used by oral introduction or mastication of food or as representative of the salt taste quality; sucrose, for drink. Foods most commonly eliciting this symptom sweet; HCl, for sour; and urea, for bitter. 'Detection are eggs, meats, poultry, fish, garlic, onions, threshold' was defined as the lowest concentration of tomatoes, coffee, chocolate, and most foods fried in solute consistently detected as different from water. oil or fat. 'Recognition threshold' was defined as the lowest concentration of solute consistently recognized correctly as salty, sweet, sour, or bitter. Taste thresh- Phantogeusia Intermittent or persistent taste per- Protected by copyright. ceived in the oral cavity independent of external olds were measured on one to four separate occa- stimuli. This taste may be salty, sweet, sour, bitter, sions in each subject. The lowest detection and metallic, or indescribably obnoxious. recognition thresholds were used for analysis when- ever more than one measurement was obtained. Heterogeusia Inappropriate consistent taste quality Olfactory acuity was measured by determining produced by oral introduction or mastication of food detection and recognition thresholds for the vapours or drink. This quality is unusual and unexpected but of pyridine in water and for nitrobenzene and thio- not necessarily obnoxious-for example, all food phene in mineral oil by a forced-choice, three- salty or sweet. stimulus sniff technique (Henkin et al., 1971; Marshall and Henkin, 1971). Smell thresholds were ABNORMALITIES OF SMELL Hyposmia General de- measured on one to three separate occasions. The crease in olfactory acuity. lowest threshold was used for analysis whenever more than one measurement was obtained. Inability to detect or recognize any vapour at primary or accessory areas of olfaction MEASUREMENTS OF METAL METABOLISM Serum con- (Henkin, 1967b). centrations of zinc and copper and 24 hour urinary http://jnnp.bmj.com/ excretion of these metals were determined. Blood and Type I hyposmia Inability to detect or recognize urine samples were collected in metal-free tubes and any vapour at primary area of olfaction but main- plastic containers, respectively, as previously de- tenance of acuity at accessory areas of olfaction scribed (Meret and Henkin, 1971). Measurements of (Henkin, 1967b). zinc and copper were carried out by atomic absorp- tion spectrophotometry on an IL Model 153 atomic Type II hyposmia Decreased acuity at primary area absorption spectrometer by a method described of olfaction with maintenance of acuity at accessory previously (Meret and Henkin, 1971). on September 23, 2021 by guest. areas of olfaction (Henkin, 1967b). SUBJECTS The experimental subjects were 29 Dysosmia General description of any distortion of patients, 17 males and 12 females, mean age 49 normal smell perception. years (range: 22 to 76 years), 28 Caucasians and one Negro (Table 1). These patients were referred to the Cacosmia Abhorrent, obnoxious smell produced Taste and Smell Clinic at the Clinical Center of the by the inhalation of odorants. Odorants which National Institutes of Health by their personal most commonly elicit this symptom are from per- physicians for evaluation of subjective complaints fumes, soaps, automobile exhaust, hair sprays, and referable to taste and/or smell abnormalities. The from most foods which elicit cacogeusia. mean duration of symptoms at the time these J Neurol Neurosurg Psychiatry: first published as 10.1136/jnnp.37.7.802 on 1 July 1974. Downloaded from

804 Paul J. Schechter and Robert L Henkin

t3 O H [+1+1+1+1+l1+ +1 +1+1+! I + + q

Q' 0i ++ ++++++I*++++++ ++ + ++++++++ +1 I!

02In

II I+++I I+I+++I + +1 +1+1+11+ + m :s IA bo ++ ++II+I+I++III+ I+ + ++I+I+++ t- 4-0 6. 110 0 C40 6L ..-;;E E. . E -;. m=e 40 Protected by copyright.

m0o mo X voooo o t!o om -

4t 0 0 szCq -.+ I +e..++±N+ ++ ++ ++ + +++ +++ + 4'. 1.

I1 1 Q 1 1 1 M 1 -LI1 1 $'' I I I I I I I I I '

.*4Y* ) . http://jnnp.bmj.com/

0. ~ .'0 E E E E E E E EE EE E E E E E E E EE E E E E E E E E E EE EE E E-4 _ " _N E-0-4 _-. EEN.EE.o.- " _" _- 0- " _-- " _* _ __4 0- 0- 0.

-* 40 -41 --41 4-4 -411 -+4~ 14t-4~! -41 -lm C4lmOe ~NM - - -- o-~el N ol e4 iN.: encl on September 23, 2021 by guest.

a o o0 0 o m C o 't t No N 'ICO 00 w 0N 'I4 'O0 mO 0o W) n It In'I tnv" N " - It It 1t " \D 't

c Cd Yd x ; -t064jttm L4 " 2244~ ..i i Cj~ 3 3 -j.4-u6 -~ 2ci:.004.0 ~ m~e ~~" a;E HoM0;w vi 6 F2 J Neurol Neurosurg Psychiatry: first published as 10.1136/jnnp.37.7.802 on 1 July 1974. Downloaded from

Taste and smell changes after head trauma 805 patients were first seen was 2- years (range: 3 analysis including specific gravity, pH, evaluation of months to 23 years). All patients had suffered head presence of glucose and bilirubin, and a micro- trauma before the onset of their symptoms and all scopic examination of the sediment. Radiographs of claimed to have had normal of taste and smell the chest, , including measurement of the before the trauma. volume of the sella turcica (DiChiro and Nelson, Twenty-four of the patients (83%) noted the onset 1962), and sinuses were carried out. A scan of changes in taste or smell immediately after the after intravenous injection of 99m Technetium was trauma or as soon as their mental state became also obtained. Results of these tests did not relate the clear. The other five patients noted onset ofsymptoms of any patient to any underlying patho- from three weeks to four months after trauma. logical aetiology other than the trauma sustained. Seven of the 29 patients (24%) suffered various fractures of the skull after trauma (documented by radiographs of the skull): occipital fractures (two), RESULTS parietal (one), basilar (two), temporal (one), and both SUBJECTIVE RESPONSES Subjective changes in basilar and parietal (one). The site of trauma to the taste and smell are shown in Table 2. Seventeen remaining 22 patients varied; however, eight of 11 patients (590%) complained of decreased taste who could specifically localize a site reported that acuity and 13 (450 trauma occurred in the occipital area. Two patients %) complained of dysgeusia. had a subdural haematoma (one right temporal Ten (340%) noted cacogeusia, six (210%) reported region, one left temporoparietal region) which were phantogeusia, and seven (24%) experienced surgically evacuated; one had an epidural haema- heterogeusia. Seven patients experienced more than one toma in the parasagittal area. specific symptom of dysgeusia and Protected by copyright. Of the 25 patients in whom this information could three reported the presence of cacogeusia, be obtained, 20 reported a period of unconsciousness phantogeusia, and heterogeusia. after trauma which lasted an extended period of time. In three patients the trauma was considered to be so trivial by the patient that medical treatment was TABLE 2 not sought. In two cases head trauma was severe enough to produce other permanent neurological SUBJECTIVE ABNORMALITIES OF TASTE AND SMELL IN deficits. PATIENTS AFTER HEAD TRAUMA The control subjects were 35 normal volunteers without disease and 60 patients with various diseases Taste but without any subjective abnormality of taste or Hypogeusia (Y) Dysgeusia (Y.) smell. These subjects were 44 Caucasian males and Cacogeusia Phantogeusia Heterogeusia 51 Caucasian females, aged 15 to 77 (mean: 39) years. The patients had diseases in which zinc and copper 59 34 21 24 metabolism was not altered. Snmell http://jnnp.bmj.com/ EVALUATION OF PATIENTS Each patient underwent Hyposmia (%) Dysosmia (%0) an extensive examination of the head and region which revealed no related to the Cacos,nia Phantosmia Heterosmia head trauma. Fungiform, circumvallate, and palatal 90 38 14 17 papillae were present in each patient and bilateral parotid salivary flow rates and pharyngeal and movements were normal. The laryngeal following on September 23, 2021 by guest. laboratory tests were performed in each patient: a Twenty-six patients (900%) complained of haematological examination including haemoglobin, decreased olfactory acuity. One patient reported haematocrit, red blood cell indices, total white decreased olfactory acuity immediately after blood cell count with a differential count, reticulo- trauma but noted a spontaneous and gradual cyte and platelet counts, and erythrocyte sedimenta- return to normal. The two other patients denied tion rate; serum sodium, potassium, chloride, carbon dioxide, , phosphorus, magnesium, any decreased olfactory acuity. Twelve patients blood sugar, urea nitrogen, creatinine, uric acid, (41%) complained of dysosmia. Of these, 11 , glutamic oxalacetic and (38%) reported cacosmia, four (14%) reported glutamic pyruvic transaminases, total protein, phantosmia, and five (170%) reported heterosmia. albumin, electrophoresis and cholesterol; urin- Five patients experienced more than one specific J Neurol Neurosurg Psychiatry: first published as 10.1136/jnnp.37.7.802 on 1 July 1974. Downloaded from

806 Paul J. Schechter and Robert L Henkin

TABLE 3 MEDIAN DETECTION AND RECOGNMON THRESHOLDS FOR FOUR TASTE QUALITIES IN 29 PATIENTS WITH HYPOGEUSIA AFTER HEAD INJURY

Taste quality Patients Normal subjects MDT/MRT Range MDT/MRT Range NaCl 75/150 6-650/30-* 12/30 6-60/6-60 Sucrose 60/90 12-800/30-* 12/30 6-60/6-60 HCI 15/90 0 8-> 500/3-> 500 3/6 0 5-6/0 8-6 Urea 650/800 90-> 8,000/90-> 8,000 120/150 90-150/90-150

MDT: median detection threshold in mM. MRT: median recognition threshold in mM. * Inability to recognize saturated solutions of NaCl or sucrose. symptom of dysosmia and three reported the OBJECTIVE MEASUREMENTS Taste Median de- presence of all three. tection and median recognition thresholds for Because of decreased palatability of food, par- four taste qualities in the patients are compared ticularly associated with dysgeusia and dysosmia, with those of control subjects in Table 3; in the nine patients (310%) sustained weight losses of 4 patients seven of eight threshold measurements to 25 pounds (2 to 5 kg). Of these nine, six were elevated above the upper limit ofthe normal experienced symptoms of cacogeusia and/or range; the median detection threshold for sucrose Protected by copyright. cacosmia. Sixteen patients (55%) reported that was the only one which was within the normal they had noticeably increased the addition of range. Four patients exhibited ageusia for NaCl to food to obtain the preferred salty taste specific tastants; for NaCl (one patient), HCI and six (21 %) noted that they had to increase the (two patients), and urea (four patients). Nine amount of sugar they normally added to their patients exhibited elevated detection and recog- food or drink to produce the preferred sweet nition thresholds for all four tastants. Fifteen taste. had elevated detection and recognition thresholds Six of the 17 patients questioned (35%0) for sucrose; 22 for NaCl; 27 for HCI; and 25 for reported a decrease in libido which was directly urea. related in time to the trauma. Whether this Each patient studied exhibited elevated detec- related to the trauma, per se, or to the sensory tion or recognition thresholds for at least one loss resulting therefrom, or both is unclear. taste quality. In four patients threshold eleva- However, patients with the syndrome of idio- tions were minimal, the major abnormality con- pathic hypogeusia, without a history of trauma, sisting of a in the recognition of sour http://jnnp.bmj.com/ often reported a similar loss of libido (Henkin et and bitter. These latter patients complained al., 1971; Schechter et al., 1972). primarily of dysgeusia. Eleven patients who

TABLE 4 AFTER MEDIAN DETECTION AND RECOGNITION THRESHOLDS FOR THREE VAPOURS IN 28 PATIENTS WITH HYPOSMIA on September 23, 2021 by guest. HEAD INJURY

Vapour Patients Normal subjects MDT/MRT Range MDT/MRT Range Pyridine 10-1/102 10 - 3_*/10 - 3-* 10 - 7/10- 3 10-8-10- 5/10 - 4-10 - 2 Nitrobenzene 10-1/A 10-3-*/10-2_* 10-6/10-3 10-7-10-5/10--01-2 Thiophene A/A 10 4-*/1 -3-* 10 - 7/10- 3 10- 8_10 - 5/10- 4-10 - 2

MDT: median detection threshold in mole/I. MRT: median recognition threshold in mole/I. A: ability to detect or recognize an absolute solution. * Inability to detect or recognize an absolute solution. J Neurol Neurosurg Psychiatry: first published as 10.1136/jnnp.37.7.802 on 1 July 1974. Downloaded from

Taste and smell changes after head trauma 807 exhibited elevations in detection and recognition several months after trauma. These observations thresholds were subjectively unaware of any suggest that patients should be observed at hypogeusia, complaining only of loss of smell. intervals subsequent to their injury in spite of the No correlations could be made between taste absence of other signs or symptoms of neuro- qualities affected, extent of taste impairment and logical dysfunction at the time of injury. severity of injury, presence or absence of skull Differentiation between delayed onset of taste fracture, locus of blow to the head, or whether a and smell abnormalities in patients after head period of followed the trauma. injury and some forms of 'idiopathic' impair- ment of taste and smell can be difficult. Aetio- Smell Median detection and recognition thresh- logical factors such as the sudden onset of the olds for three vapours in 28 of the patients are impairment after an influenza-like illness or some shown in Table 4. Each patient exhibited elevated surgical procedure (Henkin et al., 1971) or the detection or recognition thresholds for at least administration of a drug (Henkin, 1971a) are one vapour, even though three patients stated useful sources of information to help in this that they had no loss of smell acuity at the time regard. The presence of acute or chronic local of study. These latter patients subjectively com- nasal pathology such as polyps, , rhinitis, plained only of taste loss. All patients exhibited or nasal allergies is also useful. However, in detection thresholds for the three vapours tested those patients who note only a gradual, pro- which were elevated above the upper limit of the gressive diminution in acuity in taste and smell, normal range. Nine patients exhibited at least the history of a specific incident of head trauma one recognition threshold within the normal may be the only aetiological factor which can be Protected by copyright. range. One demonstrated anosmia. Thirteen used to differentiate these patients from those patients demonstrated an inability to detect or affected by the myriad of other causes of taste recognize at least one vapour. Five patients and smell abnormalities (Henkin, 1967a, b). exhibited type I hyposmia; 23 patients exhibited Quantitative measurement of taste and smell type II hyposmia. loss, presence or absence of dysgeusia, and As with taste acuity, no correlations could be measurement of serum and urinary zinc levels made between extent of olfactory loss and may also be useful to differentiate post-traumatic severity of injury, presence or absence of skull from some types of 'idiopathic' impairment fracture, locus of blow to the head, whether or (Henkin et al., 1971). not a period of unconsciousness followed the No relationship between severity of head trauma, or to the variability in time after injury injury, presence or absence of amnesia or skull at which the symptoms occurred. fracture, specific locus of injury, and severity of sensory loss could be made. However, the high incidence of occipital trauma in these patients http://jnnp.bmj.com/ DISCUSSION suggests that a blow to this area of the skull may The present study describes alterations in taste predispose to taste and smell alterations. Even and smell in 29 patients after head trauma. These minimal trauma may be sufficient to precipitate 29 comprise the single largest reported series of sensory symptoms. patients with post-traumatic loss of taste and the In all cases olfactory symptoms invariably only group in whom quantitative measurements accompany gustatory complaints. Objective of taste acuity have been determined. Although measurements of taste and smell acuity revealed on September 23, 2021 by guest. it is not possible to estimate prospectively the that elevated smell thresholds invariably accom- incidence oftaste disturbances after head trauma, panied elevated taste thresholds even if patients careful attention to the patients' complaints and did not complain of loss of smell. quantitative taste testing revealed a greater inci- Fifty-two percent (15 of 29) of the patients dence of taste abnormalities than the 0 4°/ pre- had symptoms of one or more forms of dysgeusia viously estimated (Sumner, 1967). In addition, or dysosmia. This incidence is considerably although taste and smell abnormalities usually higher than that estimated by previous investiga- occur immediately after head injury, these tors (Leigh, 1943; Sumner, 1964, 1967). In some results emphasize that symptoms can commence patients these symptoms were much more J Neurol Neurosurg Psychiatry: first published as 10.1136/jnnp.37.7.802 on 1 July 1974. Downloaded from

808 Paul J. Schechter and Robert I. Henkin

FIGURE. Total serum concen- tration ofzinc in 27 patients with hypogeusia and hyposmia after head injury (Lii) and in 95 control subjects (U). The per cent of total individuals in each category is plotted on the ordinate, serum zinc concentra- tion in 1ig/100 ml on the abscissa. Note the shift of the i distribution of the serum zinc concentrations of the patients toward the direction of lower .I than normal concentrations of !iizi zinc. *.Iz Protected by copyright. disturbing than the hypogeusia or hyposmia and TABLE 5 not uncommonly obscured the actual loss of SERUM CONCENTRATION AND URINARY EXCRETION OF ZINC sensory acuity. Indeed, because of the intensity AND COPPER IN PATIENTS AFTER HEAD INJURY AND IN of these obnoxious taste and smells some CONTROLS patients with dysgeusia and/or dysosmia con- sidered their taste and smell acuity to be more Serum (g/100 ml) Urinary (p.g/24 hr) acute than before their trauma. Zn++ Cu+ + No. Zn+ + Cu+ + No. Post- trauma METAL MEASUREMENTS Total serum zinc and patients 77±3*t 113±4* 27 482±54 31±2 22 copper concentrations and 24 hour urinary excretion of zinc and copper in the patients were Controls 99 ± 2 100± 2 95 419 ± 25 34 ± 3 67 compared with those from control subjects * P (Table 5). The patients exhibited a significant < 0-001. t Mean ± ISEm decrease in total serum zinc concentrations (P < http://jnnp.bmj.com/ 0-001) and a significant increase in total serum copper concentration (P < 0-001) compared with value. On the other hand, no patient had a total controls. Urinary zinc excretion was also slightly serum zinc concentration greater than 110 ,ug/ but not significantly higher in the patients while 100 ml, whereas 22% of the control subjects had no differences in the urinary excretion of copper serum zinc levels above this concentration. were observed. The aetiology of dysgeusia and dysosmia after The Figure illustrates the differences between head trauma is obscure. Paskind (1935) sug- on September 23, 2021 by guest. the distribution of concentration of total serum gested that dysosmia was a symptom of zinc in 95 control subjects and in 27 patients irritation which preceded anosmia or nerve with hypogeusia and hyposmia after head destruction. On the other hand, Leigh (1943) trauma. There is a shift of the distribution of suggested that dysosmia represented a stage of serum zinc levels of the patients toward the recovery from anosmia. Since dysosmia can direction of lower than normal zinc concentra- commence long after the appearance of hypos- tions. No control subject had a total serum zinc mia, Paskind's hypothesis is not tenable. Leigh's concentration below 61 ,ug/l00 ml whereas 18% suggestion also does not adequately explain the of the patients had serum zinc levels below this causation of these symptoms, since many cases J Neurol Neurosurg Psychiatry: first published as 10.1136/jnnp.37.7.802 on 1 July 1974. Downloaded from

Taste and smell changes after head trauma 809 of dysosmia and dysgeusia have been observed the time of head injury and the time they were without any subjective loss of taste or smell or observed in our clinic. without objective threshold elevations of taste We have previously demonstrated that altera- and smell (Schechter et al., 1972). tions in the metabolism of trace metals either The magnitude of the subjective complaints of drug induced (Henkin et al., 1967; Henkin and loss of smell in these patients is of interest be- Bradley, 1969; Henkin et al., 1972) or secondary cause the majority of these patients exhibited to various disease states (Henkin and Bradley, type IL hyposmia, a quantitative defect in 1969; Henkin et al., 1971; Schechter et al., 1972; olfactory acuity. This differs from type I hypos- Cohen et al., 1973) are associated with altera- mia, which characteristically follows surgical tions in taste and smell acuity. Patients with the interruption of the olfactory , extirpation syndrome of idiopathic hypogeusia with dys- of the in maxillofacial pro- geusia, hyposmia, and dysosmia exhibit de- cedures to treat carcinoma of the sinuses (Hoye creased concentrations of total serum zinc and et al., 1970), or after total surgical increased concentrations of total serum copper (Henkin et al., 1968). Many patients with type II (Schechter et al., 1972), the values being hyposmia are unaware of their sensory loss numerically quite similar to those observed in (Henkin and Marshall, 1971). However, the patients after head trauma. The oral administra- suddenness of the loss of olfactory acuity which tion of Zn + + to patients with the former syn- usually follows the head trauma may be the drome resulted in a decrease in symptoms and stimulus for the complaints of the patients. return of taste acuity towards or to normal in a The mechanism whereby a single blow to the significant number of patients (Schechter et al., Protected by copyright. head produces abnormalities of taste as well as 1972). Patients with hypogeusia after thermal smell is unclear. Post-traumatic hyposmia has injury exhibited decreased serum zinc concentra- been thought to be produced by a shearing of tions and increased 24 hour urinary excretion of filaments as they pass through zinc (Cohen et al., 1973). Administration of the the rigid cribiform plate (Ogle, 1870; Sumner, amino acid, L-, associated with a signifi- 1967). Although this hypothesis may explain the cant zincuria and subsequent hypozincaemia hyposmia resulting from trauma, it does not with a loss of total body zinc produces hypo- explain the accompanying abnormalities of geusia, hyposmia, and, not un- taste, since simultaneous bilateral damage to the commonly, dysgeusia and dysosmia (Henkin et olfactory, lingual, glossopharyngeal, and vagus al., 1972). Administration of Zn+ +, in the face of nerves does not occur in these injuries. Indeed, continued L-histidine administration, was associ- each patient in this study exhibited normal oral ated with the rapid return of serum zinc to and normal and the correction of the abnormalities papillae, salivary flow, and pharyngeal http://jnnp.bmj.com/ laryngeal function, observations which are in- oftaste and smell to normal (Henkin et al., 1972). compatible with intact sensory function of the The relationship between altered sensory percep- seventh and ninth . Further evi- tion and abnormalities of zinc metabolism has dence against such a neurological pro- been documented in various forms of liver ducing both taste and smell abnormalities is that disease (Henkin and Smith, 1971, 1972), growth this entire syndrome can occur after head trauma retardation (Hambidge et al., 1972), malabsorp- of such a mild degree that medical assistance is tive processes of several types (Henkin, unpub- not sought. In addition, this syndrome occurred lished observations), and malignancies of several on September 23, 2021 by guest. without any other residual neurological deficits types (Henkin, unpublished observations). including those of cranial nerves seven and nine Since patients with hypogeusia and hyposmia in most patients studied. after head injuries exhibit serum zinc concentra- It has been reported that in most cases of tions similar to those observed in patients with taste loss after head trauma there is a spontane- hypogeusia subsequent to zinc loss some aspects ous return of normal taste acuity with time of the altered taste and smell perception in (Sumner, 1967). This had not occurred in any of patients after head trauma may be secondary to the patients observed in this study even though alterations in zinc metabolism. If these patients intervals as long as 23 years had elapsed between were to respond to oral zinc administration in a J Neurol Neurosurg Psychiatry: first published as 10.1136/jnnp.37.7.802 on 1 July 1974. Downloaded from

810 Paul J. Schechter and Robert L Henkin

similar manner to that observed in patients with W. J. (1968). Hyposmia following laryngectomy. Lancet, 2, 479-481. idiopathic hypogeusia, then improvement in Henkin, R. I., Keiser, H. R., and Bronzert, D. (1972). these taste and smell abnormalities might be Histidine-dependent zinc loss, hypogeusia, anorexia, and expected. Studies are currently in progress to hyposmia. (Abstract.) Journal of Clinical Investigation, 51, 44a. determine if this hypothesis be correct. Henkin, R. I., Keiser, H. R., Jaffe, I. A., Sternlieb, I., and Scheinberg, I. H. (1967). Decreased taste sensitivity after D- reversed by copper administration. Lancet, 2, 1268-1271. The authors wish to thank Mrs Carol J. Franklin Henkin, R. I., Schechter, P. J., Hoye, R., and Mattern, and Mrs Diane A. Bronzert for their assistance C. F. T. (1971). Idiopathic hypogeusia with dysgeusia, during this study. hyposmia, and dysosmia. A new syndrome. Journal of the American Medical Association, 217, 434-440. Henkin, R. I., and Smith, F. R. (1971). Hyposmia in acute viral hepatitis. Lancet, 1, 823-826. REFERENCES Henkin, R. I., and Smith, F. R. (1972). Zinc and copper metabolism in acute viral hepatitis. American Journal of Cohen, I. K., Schechter, P. J., and Henkin, R. I. (1973). Medical Science, 264, 401-409. Hypogeusia, anorexia, and altered zinc metabolism Hoye, R. C., Ketcham, A. S., and Henkin, R. I. (1970). following thermal burn. Journal of the American Medical Hyposmia after paranasal sinus exenteration or laryngec- Association, 223, 914-916. tomy. American Journal of Surgery, 120, 485-491. Di Chiro, G., and Nelson, K. B. (1962). The volume of the Laemmle, H. (1931). Ueber Geruchsstorungen und ihre sella turcica. American Journal of Roentgenology, 87, 989- klinische Bedeutung. Archiv fur Ohren-, Nasen- und 1008. Kehlkopfheilkunde, 130, 22-42. Hambidge, K. M., Hambidge, C., Jacobs, M., and Baum, Leigh, A. D. (1943). Defects of smell after head injury. J. D. (1972). Low levels of zinc in hair, anorexia, poor Lancet, 1, 38-40.

growth, and hypogeusia in children. Pediatric Research, 6, Marshall, J. R., and Henkin, R. 1. (1971). Olfactory acuity, Protected by copyright. 868-874. menstrual abnormalities, and oocyte status. Annals of Henkin, R. I. (1967). Abnormalities of taste and olfaction in Internal Medicine, 75, 207-211. patients with chromatin negative gonadal dysgenesis. Meret, S., and Henkin, R. I. (1971). Simultaneous direct Journal of Clinical Endocrinology and Metabolism, 27, estimation by atomic absorption spectrophotometry of 1436-1440. copper and zinc in serum, urine, and cerebrospinal fluid. Henkin, R. I. (1967a). The definition of primary and acces- Clinical Chemistry, 17, 369-373. sory areas of olfaction as the basis for a classification of Mifka, P. (1965). Der traumatisch verursachte Verlust des decreased olfactory acuity. In Olfaction and Taste. 2, pp. Geruchs und Geschmackssinnes. In Late Sequelae of Head 235-252. Edited by T. Hayashi. Pergamon Press: Oxford. Injuries. 8th International Congress of , Vienna, Henkin, R. I. (1967b). The role of taste in disease and 1965, Proceedings, Vol. 1, pp. 379-388. Wiener Medizi- nutrition. Borden's Review ofNutrition Research, 28, 71-87. nischen Akademie: Vienna. Henkin, R. I. (1971). Disorders of taste and smell. Journal of Ogle, W. (1870). Anosmia; cases illustrating the physiology the American Medical Association, 218, 1946. and pathology of the of smell. Lancet, 1, 230-231. Henkin, R. I. (1971a). Griseofulvin and dysgeusia: implica- Paskind, H. A. (1935). in tumorous involvement of tions ? Annals of Internal Medicine, 74, 975-796. olfactory bulbs and nerves. Archives of Neurology and Henkin, R. I., and Bradley, D. F. (1969). Regulation of taste Psychiatry (Chic.), 33, 835-838. acuity by and metal ions. Proceedings of the National Schechter, P. J., Friedewald, W. T., Bronzert, D. A., Raff, Academy of Science of the United States of America, 62, M. S., and Henkin, R. I. (1972). Idiopathic hypogeusia: a

30-37. description of the syndrome and a single-blind study with http://jnnp.bmj.com/ Henkin, R. I., Gill, J. R., Jr, and Bartter, F. C. (1963). zinc sulfate. International Review ofNeurobiology, Suppl. 1, Studies on taste thresholds in normal man and in patients 125-140. with adrenal cortical insufficiency: the role of adrenal Sumner, D. (1964). Post-traumatic anosmia. Brain, 87, 107- cortical steroids and of serum sodium concentration. 120. Journal of Clinical Investigation, 42, 727-735. Sumner, D. (1967). Post-traumatic ageusia. Brain, 90, 187- Henkin, R. I., Hoye, R. C., Ketcham, A. S., and Gould, 202. on September 23, 2021 by guest.