Summary

Detailed relevant history taking and careful analysis of the information from the history, physical examination and investigation findings are of utmost importance in making a correct diagnosis. In patients presenting with memory loss and cognitive function impairment, the time course and progress of the symptoms must be clarified so that fatal disease like neoplasm would not be missed.

摘要

認真地分析詳盡的相關病史，身體檢查和分析化驗結果都是做出正確診斷的重要部分。對一個記憶力漸失和有認知能力障礙的病人，病徵的時間，發展的進度一定要留意和詳解，不然一些致命的惡性腫瘤會被延醫診治。

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Introduction

Memory impairment is a common presenting problem in primary care. Overseas studies have quoted a prevalence ranging from 6% to 78%.^1,2 There is as yet no data on the local prevalence. Very often it is not the patient who seeks help, but rather the relatives. The list of differential diagnoses for a patient presenting with memory impairment can be very long, and so a detailed history covering both physical and psychosocial aspects must be obtained in order to elucidate the underlying problem. Here we present a gentleman with memory impairment, at the same time illustrating the importance of a good history and the need for appropriate management in order that the patient can receive the most suitable care.

The history in detail

Mr Ng is a 60 year-old retired government servant, a non-smoker and non-drinker, with an unremarkable past medical history. He and his wife consulted a private doctor for a one-month history of insidious onset, progressively deteriorating memory impairment. Investigations found that he had a low serum vitamin B12 level. Other blood test results were normal. Radiological investigations were not performed at that time. He was treated with oral vitamin B12 supplement and was referred to the neurology unit at the local public hospital for further management. A routine appointment was provided. Four weeks later, he was seen for the first time at the local general outpatient clinic accompanied by five relatives including his wife and children. They expressed their deep concern about his deteriorating memory and personality change over the past two months. Both long term and short term memory were impaired. He was unable to recall his wife’s and children’s names nor was he able to recognize his relatives’ faces. He had been a cheerful, humorous and caring gentleman before, but had recently changed to be a silent and irritable man. His relatives claimed that he had become a completely different person. His wife also complained about his uninhibited behaviour, including spitting everywhere at home for no apparent reasons. In the recent one month, he had been unable to cope with normal daily living. He needed help in self-care like feeding and bathing. More importantly for his family, he was noted to be doubly incontinent. In the recent week, he had been walking with a clumsy gait. There were no associated headache, nausea or vomiting. There was no witnessed seizure, loss of consciousness or any specific focal neurological symptoms. There were no psychosis or mood symptoms, and there were no recent weight loss or constitutional symptoms. There was no recent history of head injury. Psychosocially, he had retired two months earlier from government service where he had worked for more than 30 years. Three months earlier, his mother had passed away due to cerebrovascular disease.

Physical examination found that he was walking with a clumsy gait, requiring a stick for support. He was alert but disorientated in place, time and person. Neurological examination was unremarkable. He was afebrile with blood pressure 124/ 80mmHg and pulse 71/min.

In view of the background history of deteriorating memory, impairment of cognitive function and personality change of two months duration, together with the newly occurring double incontinence and clumsy walking gait, an intracranial space-occupying lesion must be ruled out. Other differential diagnoses included intracranial infection, cerebrovascular accident, normal pressure hydrocephalus (classic triad of mental declines, urinary incontinence and gait disturbance) and the rare neurodegenerative diseases. Because further sophisticated investigations were not available in a general outpatient clinic setting, he was therefore referred to the accident and emergency department (AED) for urgent investigation and management.

A computerized tomographic (CT) brain scan performed at the AED found a 6.2 x 5.1 x 5.1 cm mass in the left frontal lobe. He was admitted to the neurosurgical ward for management. CT brain with contrast and MRI findings concluded that the mass was a predominantly cystic lesion with an enhancing solid area and septa in the left frontal lobe associated with peri-lesional oedema and mass effect with left uncal herniation. Malignancy was highly suggestive.

Surgery was performed on the 8^th day of admission. Total excision of the brain lesion (left craniotomy + Simpson II excision) was carried out. Histological finding confirmed a diagnosis of atypical meningioma.

Discussion

In 2006, according to the Hong Kong Cancer Registry of the Hospital Authority, there were 195 new cases of brain and central nervous system (CNS) cancer in both sexes of all ages.³ The crude incidence rate was 2.8 per 100,000. 98 died of brain and CNS cancer, and the crude mortality rate was 1.4 per 100,000. In 2006, brain and CNS cancer ranked 19^th in the cumulative risk of the 20 leading cancer sites of cancer mortality. The sex ratio of brain and CNS cancer deaths was 1.4:1 (male to female). The median age at death was 52 years in male and 56 years in female. The cumulative risk of dying from brain and CNS cancer was 1 in 810 and 1 in 996 in males and females respectively.^3,4

Brain tumours, whether benign or malignant, can be fatal if not treated. 15% of brain tumours are metastatic tumours with primaries from breast, lung, kidney, colon or melanoma. Over 50% are neuroepithelial in origin, 15% are meningiomas and 8% are pituitary tumours. Glioma is the commonest adult intracranial tumour which accounts for 50% of the cases and are neuroectodermal in origin.⁵

Meningiomas are meningothelial in origin.^5,7 Although there is a spectrum of histological appearances, malignant meningiomas are relatively rare.⁵ Surgery is the main stay of treatment.^5,6 Based on the WHO classification systems,^7-10 meningiomas are classified as:

1. Benign (Grade I) (90%) – meningothelial, fibrous, transitional, psammomatous, angioblastic

2. Atypical (Grade II) (7%) – choroid, clear cell, atypical

3. Anaplastic/malignant (Gr ad e II I) (2%) – papillary, rhabdoid, anaplastic.

Frontal lobe syndrome is a disorder affecting the prefrontal region of the frontal lobe, characterized by a sudden and dramatic change in personality. It can be due to head injury, stroke, infection, neoplasm and degenerative diseases such as Pick’s disease. Symptoms include loss of attention, impaired working or short-term memory, loss of abstract thinking, preservation behaviour, change of affect and disinhibited behaviour such as inappropriate sexual behaviour.^9-11

Learning points in the case

Importance of history taking:

1. Be cautious about the time course and progress of symptoms
   
   The presentation of memory loss and cognitive function impairment for only two months duration is too short for the diagnosis of dementia to be made. The rapid deterioration of symptoms and the new onset of neurological symptoms including double incontinence and clumsy gait point to an evolving focal intracranial pathology that demands immediate action in order to look for the exact underlying aetiology.
    
2. Remember to seek relevant information from family members
   
   Patients with cognitive impairment usually cannot give much relevant information about their own symptoms but their family members can. Therefore, we should never miss the chance to seek every bit of relevant information from the family members.

Careful analysis of the information from the history and investigation findings:

1. Frontal lobe syndrome has to be considered when a patient is noted to have sudden change of personality, change in affect or behaviour.

2. Given the psychosocial history of recent retirement and bereavement, the differential diagnoses of pathological bereavement and depression are possible; but they cannot explain the focal neurological symptoms.

3. The presence of vitamin B12 deficiency cannot account for the rapid deterioration of neurological symptoms.

Do not panic when the patient comes with a group of relatives/ friends:

If a large group of relatives/friends insists on accompanying the patient into the consultation room, it may mean that the patient’s illness/disease is severe enough to arouse their serious concern. They, or at least some of them, may provide important information and clues for us to make the correct diagnosis. It can also be a good opportunity to get them involved in the patient’s care and decision making process. Therefore, be alert when your consultation room is crowded with people and do not need to fear that they may find faults or make troubles.

Key messages

1. When encountering patients presenting with memory loss and cognitive function impairment, the time course and progress of symptoms must be clarified so that fatal disease like neoplasm would not be missed.
2. Detailed analysis of information from the history, physical examination and investigation findings are of utmost importance in making a correct diagnosis.
3. Be alert when patient comes with a group of relatives or friends as they may provide important information and clues for us to make the correct diagnosis.

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References