What are the signs of Pick's disease?

Signs of Pick's Disease

Pick's disease typically presents with progressive behavioral and personality changes, speech disturbances, and characteristic eating behaviors, often beginning before age 65, with relative preservation of memory in early stages. 1, 2

Clinical Presentation by Syndrome

Pick's disease (a specific neuropathologic subtype of FTLD-tau) most commonly manifests through two distinct clinical syndromes:

Behavioral Variant (62% of cases)

Progressive dysexecutive and/or behavioral syndrome is the most common presentation 3:

• Personality changes (frontal type):

  • Disinhibition and socially inappropriate behavior
  • Loss of empathy and emotional blunting
  • Apathy and loss of motivation/initiative
  • Impaired judgment and poor decision-making 1, 4

• Characteristic behavioral features:

  • Hyperorality (compulsive eating, food preferences changes, bulimia)
  • Roaming behavior (purposeless wandering)
  • Reiterative behaviors and verbal stereotypies
  • Compulsive or obsessive behaviors 4, 5

• Cognitive features:

  • Executive dysfunction (reasoning, problem-solving, planning)
  • Relatively preserved memory for recent events in early stages (distinguishes from Alzheimer's)
  • Attention and concentration difficulties 4, 5

Language Variant (38% of cases)

Progressive aphasic syndrome 3:

• Word-finding difficulty (anomia)
• Speech sound errors
• Agrammatism
• Impaired comprehension (in semantic variant)
• Reading and writing impairment (alexia, agraphia) 1

Motor and Neurological Signs

Motor features can occur, particularly as disease progresses 1:

• Parkinsonism (bradykinesia, rigidity, parkinsonian gait) - may be asymmetric
• Limb apraxia (difficulty performing learned motor tasks)
• Dystonic posturing
• Myoclonic jerks 6
• Primitive reflexes (grasp reflex)

Early vs. Late Disease Features

Early-phase Pick's disease may present subtly 7:

• Predominant apathy that may be misdiagnosed as depression
• Minimal behavioral symptoms initially
• Behavioral disinhibition may only become apparent with careful observation
• Family members may not recognize early behavioral changes

Disease progression 3:

• Behavioral variant: average survival 7 years from onset
• Language variant: average survival 12 years from onset
• Progressive cognitive decline always occurs eventually

Key Distinguishing Features from Alzheimer's Disease

The combination of three or more of these features strongly suggests Pick's disease over Alzheimer's 4:

1. Presenile onset (before age 65)
2. Initial personality change (rather than memory loss)
3. Hyperorality
4. Disinhibition
5. Roaming behavior

Neuroimaging Findings

• Circumscribed frontotemporal atrophy (frontal and temporal poles)
• Atrophy of caudate nucleus
• Disproportionate parietal lobe atrophy may occur 5, 6
• Striking normality of EEG (unlike Alzheimer's disease) 5

Clinical Pitfalls

Common misdiagnoses include:

• Depression (especially in early apathetic presentations) 7
• Primary psychiatric disorders (psychosis, personality disorders) 8
• Alzheimer's disease (when memory appears affected)
• Idiopathic Parkinson's disease (when motor features predominate) 6

Critical diagnostic clues:

• Normal or near-normal performance on MMSE in early stages despite obvious behavioral changes 9
• Lack of insight into behavioral changes (anosognosia)
• Behavioral symptoms that are atypical or poorly responsive to psychiatric treatment 9

Neuropathologic Context

Pick's disease represents a specific FTLD-tau pathology characterized by Pick bodies (3-repeat tau inclusions), predominantly affecting frontal and temporal lobes, hippocampus (especially dentate gyrus), and amygdala 2, 3. The clinical syndrome reflects the anatomic distribution of pathology, with dorsolateral frontal involvement producing apathy and executive dysfunction, while orbitofrontal/temporal involvement produces disinhibition and behavioral changes 7.