Atypical presentation of frontotemporal dementia masquerading as bipolar disorder and substance abuse: a case report.
Abstract: This is the case of a 44 year old man with frontotemporal lobar dementia whose presentation was consistent with Bipolar Affective Disorder with psychosis in addition to ongoing substance abuse. Despite extended periods of sobriety and multiple medications to target Bipolar Disorder, his symptoms remained refractory. With repeated brain imaging and progression of the disease, frontotemporal dementia was diagnosed. The patient went on to develop Amyotrophic Lateral Sclerosis (ALS), which is known to overlap the neuropathological features with frontotemporal lobar dementia. (6) Respiratory compromise ultimately led to this patient's death, which was deemed secondary to ALS. This case demonstrates the need for clinicians to recognize differential diagnoses in manic and psychotic symptoms resistant to polypharmacy.
Article Type: Case study
Subject: Dementia (Diagnosis)
Dementia (Case studies)
Bipolar disorder (Diagnosis)
Bipolar disorder (Case studies)
Substance abuse (Diagnosis)
Substance abuse (Case studies)
Author: Ibanez, Noel
Pub Date: 07/01/2012
Publication: Name: West Virginia Medical Journal Publisher: West Virginia State Medical Association Audience: Academic Format: Magazine/Journal Subject: Health Copyright: COPYRIGHT 2012 West Virginia State Medical Association ISSN: 0043-3284
Issue: Date: July-August, 2012 Source Volume: 108 Source Issue: 4
Geographic: Geographic Scope: United States Geographic Code: 1USA United States
Accession Number: 310150680
Full Text: Introduction

The symptoms of impaired executive functioning, psychosis, affective dysregulation, concurrent with substance abuse, present clinicians with a broad list of differential diagnoses. Once all metabolic and organic medical causes have been excluded, there still remain several psychiatric illnesses of possible etiology. When taking into account ongoing substance abuse with mood dysregulation in a 44 year old man without previous history of impairments, the diagnosis of dementia falls low on the differential list. Frontotemporal lobar dementia is the second most common dementia after Alzheimer's affecting persons in middle age, and accounts for up to 20% of presenile dementia cases. (2) Frontotemporal lobar degeneration is a broad diagnostic term that encompasses multiple distinct forms of a dementia syndrome, with the three major subtypes being frontotemporal dementia, semantic dementia (concept based memory loss), and primary progressive aphasia. Depending on the clinical subtype, these individuals can present in a number of ways including behavioral problems, memory disturbances, and language dysfunction. It is the opinion of this examiner that the early onset of symptoms with impulsivity and thoughtless behaviors, with concurrent alcohol and benzodiazepine abuse, had delayed the diagnosis of this relatively rare disease.

Case Report

The patient was a 44 year old male who presented to the emergency department after court ordered detainment for mental hygiene evaluation due to the man's increasingly bizarre behaviors. The petitioner described a two year history of worsening paranoia of friends and business contacts (noted to be a successful architect), delusions that UFO's were following him, and that he was visited by his deceased father and grandfather. In addition to these symptoms, it was reported that his alcohol consumption had increased in frequency, resulting in risk taking and careless behaviors exemplified by driving while intoxicated; he also had been abusing a Temazepam prescription. Physical examination, laboratory work, and brain imaging were negative for organic, infectious, or metabolic etiology. Diagnostic clarification was consistent with late onset Bipolar disorder type I, manic with psychotic features and abuse of alcohol and benzodiazepines that started when his mania progressed. Despite reports of sobriety spanning several months along with numerous psychotropic medication trials with mood stabilizers, anti-psychotics, and anti-epileptic drugs, his manic and psychotic symptoms remained refractory. Over the ensuing 6 to 12 months, his bizarre behaviors and psychosis continued, however with elevated aggression, such as threatening family members with knives. Objective findings with subsequent admissions were significant for psychomotor retardation, slow perseverative speech, and impaired concentration and memory on mental status examination. MRI of the brain repeated sixteen months later demonstrated slight progression of atrophy in the tempoparietal regions that was very subtle on previous imaging. Follow up study with PET CT of the brain demonstrated abnormal metabolic decrease throughout the brain, though with strikingly decreased metabolic activity symmetrically in bilateral frontal and anterior temporal lobes. The brain imaging findings in the setting of decline in social conduct and departure from customary behavior, all supported the eventual diagnosis of frontotemporal lobar dementia. Ultimately, the aggressive behaviors were treated with pharmacotherapy and supportive services were established.

Discussion

Frontotemporal lobar dementia is a neuropathological disorder involving degeneration of the frontal and/or temporal lobes, sometimes involving the parietal lobes. Age of onset is most common between 45 and 65. There is an equal incidence between men and women. (2) The most common clinical findings include personality changes, dramatic changes in social conduct and behaviors, and language abnormalities.

Frontotemporal lobar degeneration is a diagnostic term that encompasses multiple distinct forms of this dementia syndrome, with the three major subtypes being frontotemporal dementia, semantic dementia, and primary progressive aphasia. For purposes of this case report, the frontotemporal dementia behavioral variant will be the focus. Frontotemporal dementia behavioral variant is the most common diagnostic subgroup, with over half of the diagnoses falling under this category. (3) It has been further proposed that among the behavioral variants of frontotemporal dementia, distinct anatomical patterns of grey matter loss directly correlate with an even more detailed classification of the behavioral variant subtype. Studies have demonstrated that depending on the general location of atrophy, several variants of behavior abnormalities can result. For example, frontal dominate atrophy is found to have significant dysfunction of executive functions. Temporal dominate atrophy has clinical findings with significantly worse memory performance. When involved, parietal lobe atrophy often presents with aphasia. (1) It is critical to keep these behavioral variant subtypes in mind when evaluating the above patient. When the patient initially presented, there were only subtle findings of fronto-temporal-parietal atrophy on MRI imaging. However, with disease advancement evident by clinical deterioration, repeat imaging revealed significant progression in atrophy of the frontal and temporal lobes, though with generalized atrophy being noted.

In hindsight, the findings of this patient's executive dysfunction directly correlated with his frontotemporal atrophy. However, arriving at this patient's diagnosis was a difficult task for various reasons. First of all, his youth at age 44 was atypical in itself for frontotemporal lobar dementia. His concurrent use of alcohol also confounded the evaluators, given that intoxication and recurrent use clearly impact executive functions and memory. Additionally, the symptoms of grandiosity, distractibility, psychomotor agitation, and his thoughtless behaviors with gratifying a need to engage in pleasurable activity, all lead evaluations toward an alternative diagnosis of a manic episode, and consequently a diagnosis of bipolar disorder. It was not until after disease progression in spite of multiple medication trials, and repeated imaging demonstrating the increased brain atrophy, did the diagnosis of frontotemporal lobar degeneration declare itself.

Conclusion

Frontotemporal lobar dementia is a relatively rare disorder that presents with a number of symptoms, many of which overlap those similar to mania, psychosis, and substance abuse disorders. When clinicians do not constantly maintain a differential diagnosis, especially in patients resistant to appropriate pharmacotherapy, the diagnosis can often be delayed or even missed.

References

(1.) Whitwell JL, Przybelski SA, Weigand SD, Ivnik RJ, Vermuri P, Gunter JL, Senjem ML, Shiung MM, BoeveBF, Knopman DS,Parisi JE, Dickson DW, Peterson RC, Jack CR, Josephs KA: Distinct anatomical subtypes of the behavioural variant of frontotemporal dementia: a cluster analysis study. Brain: A Journal of Neurology 2009; 232-247.

(2.) Snowden JS, Neary D, Mann DMA: Frontotemporal Dementia. British Journal of Psychiatry 2002; 140-143.

(3.) Bozoki AC, Farooq MU: Frontotemporal lobar degeneration: Insights from neuropsychology and neuroimaging. International Review of Neurobiology, Vol 84; 185-213.

(4.) Kertesz A, Munoz D: Relationship between frontotemporal dementia and corticobasilar and corticobasilar degeneration/Progressive supranuclear palsy. Dementia and Geriatric Cognitive Disorders 2004; 17:282-286.

(5.) Joseph R: Frontal lobe psychopathology: mania, depression, confabulation, catatonia, perseveration, obsessive compulsions, and schizophrenia. Psychiatry, 1999; 62: 138-72.

(6.) Giordana MT, Ferrero P, Grifoni S, Pellerino A, Naldi A, Montuschi A: Dementia and cognitive impairment in amyotrophic lateral sclerosis: a review. Neurology Science, Nov 2009.

Noel Ibanez, MD

Chief Resident, Dept. of Psychiatry

WVU, Morgantown
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