Corticobasal Degeneration (CBD)

Corticobasal Degeneration (CBD) is the rarest of the four atypical parkinsonism disorders. Depending on whom you ask, it’s classified as an atypical parkinsonism disorder, a non-Alzheimer’s dementia, or a type of frontotemporal degeneration. CBD is most closely similar to PSP in terms of symptoms and pathology. Many organizations that perform research on PSP also research CBD.

CBD Symptoms

Because CBD is so rare, research has been very limited. Most studies of autopsy-confirmed disease only include a few dozen cases. It’s hard to be definitive with such small numbers.

The medical community now uses the term CBS or corticobasal syndrome to refer to a clinical diagnosis. CBD or corticobasal degeneration is now used for an autopsy-confirmed diagnosis.

Since 2013, CBD experts refer to four main types of CBD:

  • Corticobasal syndrome: limb rigidity; limb akinesia (lack of movement); limb dystonia; myoclonus (jerky movements); limb apraxia (difficulty using a limb not due to motor of sensory problems); orobuccal (mouth and cheek) apraxia; cortical sensory deficit (inability to discern a sensation); alien limb phenomena (the limb seems to have a mind of its own). We could describe this type as “classic CBD.”
  • Frontal behavioral-spatial syndrome: executive dysfunction; behavioral or personality changes; visuospatial deficits. This type may look like the behavioral variant of frontotemporal dementia.
  • Nonfluent/agrammatic variant of primary progressive aphasia: effortful, agrammatic speech; impaired grammar/sentence comprehension; apraxia of speech (groping, distorted speech production). This type may look like a type of frontotemporal degeneration called primary progressive aphasia (PPA).
  • Progressive supranuclear palsy syndrome: axial rigidity; limb rigidity; akinesia; postural instability or falls; urinary incontinence; behavioral changes; supranuclear vertical gaze palsy; decreased velocity of vertical saccades. This type looks like PSP.

The symptoms of these four types are so different that they seem to be entirely different disorders.

CBD Treatments

There is remarkably limited treatment for CBD/CBS. The most effective treatments are the therapies: physical therapy, occupational therapy, and speech therapy. Therapies are pinpointed on prevention of falls and aspiration pneumonia.

Exercise is key for fall prevention and maintaining mobility. A member of our local support group was told by his wife’s movement disorder specialist that she lived an additional two years due to exercise on a special treadmill.

The medication that can be prescribed and any other treatments are focused on a few symptoms that may respond to medication or treatments such as depression, urinary incontinence, and dry eyes. There is no evidence that any of the Parkinson’s medications (levodopa therapy) or Alzheimer’s medications are helpful in CBD/CBS.

Go-To Organizations for CBD Education

A handful of organizations consistently deliver quality information about CBD. Click the link for each organization to review their web sites:

Organization Name Country Focus Web Address
CurePSP USA Increase awareness, fund research, educate health professionals, support patients & families
PSP Association UK Support patients & families, provide education PSPA

CBD Top Resources

Brain Support Network continually reviews most of the resources available on CBD. In our opinion, these are the most helpful resources for families:

Treating Progressive Supranuclear Palsy (PSP), Multiple System Atrophy (MSA), and Corticobasal Degeneration (CBD) – What can be done?

Movement disorder specialist Dr. Brent Bluett describes the symptomatic treatments possible for MSA that can improve quality of life. His message:  Each treatment individually may be minor, but in sum they can make a significant difference. There is always hope! This February 2019 webinar was co-hosted by Stanford University and Brain Support Network.

> Detailed notes:

> Recording:

Corticobasal Syndrome & Corticobasal Degeneration, Basics & What You Need to Know

This 92-minute AFTD webinar from March 2020 provides an in-depth look at corticobasal syndrome and corticobasal degeneration, clarifies vocabulary, how a diagnosis is made, common symptoms, expected progression, and treatment approaches.


Evaluating and Treating Urinary Issues in Parkinson’s Disease (PD), Multiple System Atrophy (MSA), and Other Atypical Parkinsonism Disorders

Urologist Dr. Ekene Enemchukwu focuses on urinary incontinence, overactive bladder, urinary retention, nocturia, and other urinary issues. This August 2019 webinar was co-hosted by Stanford University and Brain Support Network.

> Detailed notes:

> Recording:

UCSF Memory & Aging Center Overview of CBS

This is a good overview of the signs and symptoms of CBS.


The AFTD Overview of CBS

This is a good overview of the three categories of clinical features of CBS.


Your Personal Guide to PSP (and CBD)

The first section of this 110-page booklet has an excellent introduction to PSP and CBD, with a focus on symptoms such as cognition/mood, mobility/falls, fatigue/ sleep, pain, swallowing, vision, and bladder/bowel. Other sections focus on the care team, caregiving, etc.  Published April 2013 by The PSP Association (UK). The group uses the term “PSP” as shorthand for both conditions.

> Section 1:
> Section 2:
> Section 3:
> Section 4:

UCSF PSP/CBD Research Update

This Februray 2014 conference focused on what UCSF Memory and Aging Center researchers have learned thus far about PSP and CBD, and what research is underway. Most of the eight talks are about 14 minutes in length.


Update on PSP and CBD

This update was given by neurologist Dr. Rajeev Kumar at the CurePSP family conference in Denver in October 2013. Recorded presentation is available online.


Person-Centered Care for Corticobasal Syndrome and Progressive Supranuclear Palsy

This 55-minute AFTD webinar from November 2022 is aimed at healthcare professionals. It provides an overview of CBS and PSP symptoms and treatments, explains how both disorders differ from Parkinson’s, and highlights approaches to support patients and family caregivers.


Cognitive Changes in Movement Disorders CBS and PSP

This 47-minute AFTD webinar from May 2024 provides an overview of these CBS and PSP, with an emphasis on how they fit into the broader FTD spectrum, including the ways they overlap with other FTD subtypes.


Assessing Cognitive Changes with PSP, CBD and MSA

This 74-minute recording is an episode of the AFTD webinar series Ask the Expert from June 2023. Travis Turner, PhD, provides a brief overview of the cognitive changes associated with PSP, CBD and MSA, describes the neuropsychological evaluation process, and discusses how the information obtained informs diagnosis, prognosis and treatment planning.


A Professional’s Guide to Corticobasal Degeneration

This is a terrific 14-page guide for healthcare and social care professionals about CBD.  The guide sets out the “standards of care people with CBD, their carers and family members should expect.” Published November 2018 by The PSP Association (UK).


Exploring diagnosis, management and best practice interventions in relation to PSP, MSA, and CBD

This November 2009 conference for allied health professionals (RNs, PTs, OTs, STs, social workers, etc) in Melbourne, Australia was recorded. One of the world’s top researchers of CBD, Dr. David Williams, based in Melbourne, is featured. The multi-hour conference is broken into 10-minute online video segments.  The first part of one segment is about CBD.


> Notes on video:


This 140-page resource on PSP (mostly), CBD, and MSA was updated by CurePSP in 2020. Topics include incontinence, constipation, dry eyes, and visual issues.

Care Partner Guidebook

This 76-page booklet updated in 2020 outlines managing care and getting professional support, being a care partner, making plans, and care partners’ perspectives and pointers. “From our Caregivers” section is advice from PSP care partners.



Top Resources – Oldies but Goodies

These are all older resources that we hate to give up on because they are well-done summaries of MSA.  However, because of the publication dates, there may be outdated information.

Treatment of and Research on CBS/CBD

Dr. Irene Litvan, one of the world’s top experts on CBD, gave an excellent hour-long update at the October 2012 atypical parkinsonism symposium, organized by Stanford University and Brain Support Network. The event was held in Burlingame, CA.


Challenges in the Management of CBD

This October 2010 update on CBD was given by Dr. Litvan, one of the world’s top experts on CBD. In this CurePSP webinar, Dr. Litvan reviews the three common clinical presentations of CBD. The recorded presentation is no longer available online.

> Notes on webinar:

Behavior/Cognitive Issues with PSP, CBD & FTD

This CurePSP webinar was presented by Dr. Brad Boeve, one of the US’s experts on CBD, in April 2010. Dr. Boeve examines how various CBD symptoms are managed.

> Webinar in WAV file format (from BSN web site):

> Webinar in WAV file format (from web site):

> Notes on webinar:

A Guide for People Living with PSP, CBD, and Other Atypical Parkinsonian Disorders

122-page booklet from CurePSP, last updated in September 2012.

Finding Meaning with Charles

Book by Janet Edmunson, whose husband Charles had CBD.


Diagnostic Criteria

The diagnostic criteria listed in this section are derived from the paper Criteria for the diagnosis of corticobasal degeneration, Armstrong, et al. published in Neurology in 2013.

The paper explains CBD in terms of four distinct types (“phenotypes”) of the disease. These are:

  • corticobasal syndrome (CBS)
  • frontal behavioral-spatial syndrome (FBS)
  • nonfluent/agrammatic variant of primary progressive aphasia (naPPA)
  • progressive supranuclear palsy syndrome (PSPS)

Proposed clinical phenotypes (syndromes) associated with the pathology of corticobasal degeneration (“Table 4” in Armstrong, et al.)

Syndrome Features
Probable corticobasal syndrome Asymmetric presentation of 2 of:

a) limb rigidity or akinesia,

b) limb dystonia,

c) limb myoclonus plus 2 of:

  • d) orobuccal or limb apraxia,
  • e) cortical sensory deficit,
  • f) alien limb phenomena (more than simple levitation)
Possible corticobasal syndrome May be symmetric: 1 of:

a) limb rigidity or akinesia,

b) limb dystonia,

c) limb myoclonus plus 1 of:

  • d) orobuccal or limb apraxia,
  • e) cortical sensory deficit,
  • f) alien limb phenomena (more than simple levitation)
Frontal behavioral-spatial syndrome Two of:

a) executive dysfunction,

b) behavioral or personality changes,

c) visuospatial deficits

Nonfluent/agrammatic variant of primary progressive aphasia Effortful, agrammatic speech plus at least one of:

a) impaired grammar/sentence comprehension with relatively preserved single word comprehension, or

b) groping, distorted speech production (apraxia of speech)

Progressive supranuclear palsy syndrome Three of:

a) axial or symmetric limb rigidity or akinesia,

b) postural instability or falls,

c) urinary incontinence,

d) behavioral changes,

e) supranuclear vertical gaze palsy or decreased velocity of vertical saccades

Proposed clinical phenotypes (syndromes) associated with the pathology of corticobasal degeneration (“Table 5” in Armstrong, et al.)

Clinical research criteria for probable sporadic CBD Clinical criteria for possible CBD
Presentation Probable corticobasal syndrome Asymmetric presentation of 2 of:

a) limb rigidity or akinesia,

b) limb dystonia,

c) limb myoclonus plus 2 of:

  • d) orobuccal or limb apraxia,
  • e) cortical sensory deficit,
  • f) alien limb phenomena (more than simple levitation)
Minimum duration of symptoms (years) 1 1
Age at onset (years) ≥50 No minimum
Family history (2 or more relatives) Exclusion Permitted
Permitted phenotypes (see table 4 for criteria) 1) Probable CBS or
2) FBS or NAV plus at least one CBS feature (a–f)
1) Possible CBS or
2) FBS or NAV or
3) PSPS plus at least one CBS feature b–f
Genetic mutation affecting tau (e.g., MAPT) Exclusion Permitted