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Advanced Neurology Dementia with Lewy bodies and substance misuse

decline that is sufficient to interfere with activities of daily misuse. The fluctuating cognition and mobility, which
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living (ADL). Neuropsychological testing often reveal would normally point toward DLB, can be seen as signs of
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deficits in attention, executive function, and visuospatial substance misuse or polypharmacy in a patient with a history
abilities, while deficits in memory may not be apparent in of SUD. However, a history of substance misuse should
the early stages of the disease. Diagnosis of potential DLB not preclude DLB or other forms of dementia as possible
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is “probable” or “possible” based on the presence of clinical diagnoses, as SUD can contribute to the development
features and biomarkers (Table 1). of neurodegenerative dementias. 12-14 These degenerative
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For a diagnosis of probable DLB, two of more clinical disorders are believed to have multifactorial causes, which
features must be present or one core clinical feature with one may include viruses, toxins, head trauma, psychological
or more indicative biomarkers. To confirm a diagnosis of stressors, and genetic factors, among others. 15,16 If not the
possible DLB, only one clinical feature must be present, or primary causative factor, alcohol and benzodiazepines may
positive expression of one or more biomarkers without the hasten the progression of neurodegenerative dementias. 12,14,17
presentation of any associated clinical features suffices for the Individuals presenting with worsening cognitive deficits with
diagnosis. If other disorders such as cerebrovascular disease or without Parkinsonian symptoms, either by self-report or
explain some of the symptoms, DLB cannot be fully excluded as reported by the patient’s family, should be evaluated for
as mixed pathologies are possible. DLB is also possible if neurodegenerative dementias, regardless of SUD history.
Parkinsonian symptoms are the only core clinical feature and In this paper, we review the challenges, including
appear late in dementia progression. PDD is indicated when limitations of standardized instruments for dementia
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dementia occurs after Parkinson’s disease has been long and the harms of delayed diagnosis, in DLB diagnosis,
established. Reliance on obtaining a reliable history from the largely based on our experiences drawn from studying a
patients (such as whether they have hallucinations or sleep polypharmacy-practicing 68-year-old Caucasian male
abnormalities) along with possible uncertainty of the etiology with a 40-year history of benzodiazepine use and alcohol
of Parkinsonian symptoms in patients with polypharmacy use disorder (AUD). The patient had been seeing different
can contribute to delay in early diagnosis. 10 providers for over 5 years with multiple neurological
When a patient has a history of substance use disorder complaints, which were always attributed to his SUD.
(SUD), it can complicate the diagnosis process as symptoms The patient’s medical records, however, led us to believe a
of dementia can be confused with the side effects of degenerative dementia was involved.

Table 1. Clinical criteria for diagnosis of dementia with Lewy bodies
Core clinical features Indicative biomarkers
Fluctuating cognition with variations in attention and alertness Reduced dopamine transporter uptake in basal ganglia on
SPECT or PET imaging
Vivid visual hallucinations Low uptake of iodine, as detected by MIBG myocardial
scintigraphy 7
REM sleep behavior disorder Polysomnographic confirmation of REM sleep without
atonia
One or more cardinal symptoms of Parkinsonism (bradykinesia, rigidity,
tremor, and postural instability), which occur spontaneously
Supportive clinical features Supportive biomarkers
Postural instability including dizziness, syncope, pre-syncope, or transient Relative preservation of medial temporal lobe structures on
periods of unresponsiveness CT/MRI scan
Severe autonomic dysfunction (orthostatic intolerance, constipation, bowel Generalized low uptake on SPECT/PET perfusion/
incontinence, urinary incontinence, urinary retention, dry mouth, nausea, metabolism scan with reduced occipital activity±the
erectile dysfunction, hyperhidrosis, heat intolerance, palpitations, etc.) 8,9 cingulate island sign on FDG-PET imaging
Non-visual hallucinations and/or systemized delusions Prominent posterior slow wave activity on EEG with periodic
fluctuations in the pre-alpha/theta range
Apathy, anxiety, or depression
Hypersomnia or hyposomnia
Severe sensitivity to antipsychotic medications
Notes: Two or more clinical features or one core clinical feature with one or more indicative biomarkers indicate probable DLB. One clinical feature or
one or more biomarkers indicate possible DLB. Abbreviation: DLB: Dementia with Lewy bodies.

Volume 3 Issue 1 (2024) 2 https://doi.org/10.36922/an.2232