This is a rather weak study because they looked at 10 patients with the clinical diagnosis of PSP and 11 patients with the clinical diagnosis of CBD. No pathological confirmation was available. Their findings included:
* “Photophobia occurred in all 10 (100%) PSP patients vs 2 (18%) patients with clinically suspected CBD (p=0.0002).” And: “The presence of photophobia is significantly more frequent in clinically diagnosed PSP than CBD and can be used as a feature in differentiating between the two diseases in clinical practice.”
Every PSPer I’ve met has photophobia and some (but not all) of the CBDers I’ve met have photophobia.
* “Visual hallucinations and RBD occurred in patients with PSP and CBD but were rare occurrences (5% for each symptom).” And: “Visual hallucinations and RBD occur infrequently in PSP and CBD and are not useful symptoms in clinical differentiation.”
I usually hear “photophobia” called “photo sensitivity.” Whenever I was in the hospital or skilled nursing facility with my dad, I’d always close the blinds/curtains and, if there was an overhead light on, we’d put sunglasses on dad or a washcloth over his eyes to block out the light. “Photophobia” is extreme sensitivity or aversion to sunlight and any other light.
Robin
Parkinsonism & Related Disorders. 2008 Mar 5 [Epub ahead of print]
Photophobia, visual hallucinations, and REM sleep behavior disorder in progressive supranuclear palsy and corticobasal degeneration: A prospective study.
Cooper AD, Josephs KA.
Department of Neurology, Mayo Clinic, Rochester, MN.
Progressive supranuclear palsy (PSP) and corticobasal degeneration (CBD) have overlapping clinical features that can make clinical distinction between these two entities difficult. The present study compared the frequency of photophobia, visual hallucinations, and REM sleep behavior disorder (RBD) in patients clinically diagnosed with PSP to those clinically suspected to have CBD. Photophobia occurred in all 10 (100%) PSP patients vs 2 (18%) patients with clinically suspected CBD (p=0.0002). Visual hallucinations and RBD occurred in patients with PSP and CBD but were rare occurrences (5% for each symptom). The presence of photophobia is significantly more frequent in clinically diagnosed PSP than CBD and can be used as a feature in differentiating between the two diseases in clinical practice. Visual hallucinations and RBD occur infrequently in PSP and CBD and are not useful symptoms in clinical differentiation.
PubMed ID#: 18328771 (see pubmed.gov for abstract only)
I received a copy of this full article today. In my earlier post, after reading the abstract only, I concluded that no cases in this Mayo Rochester study had been pathologically-confirmed. This is incorrect. The full article notes that “Ten patients had PSP, two with pathologic confirmation, and 11 patients had CBS, one with pathologic confirmation.”
These patients (and their significant others) were questioned regarding photophobia. “The question regarding photophobia emphasized discomfort as a result of light exposure as opposed to frequent eye closing or lack of eye opening. This distinction is important since both blepharospasm and apraxia of eye opening can be present in these disorders.”
The findings were: “Photophobia occurred in all 10 (100%) PSP patients vs 2 (18%) CBS patients. The mean time between when the patient first reported photophobia and disease onset was 3.1 years.” Based upon this, the authors argue that “the presence of photophobia may help clinicians to better differentiate between PSP and CBS on a clinical basis…”
Interestingly, of the 2 CBS patients with photophobia, one of these was pathologically-confirmed as CBD. And, “both CBS patients with photophobia were two of only three CBS patients with vertical gaze palsy suggesting pathological involvement of brainstem nuclei in these two subjects.”
The authors admit that they need more pathologically-confirmed cases.
This finding was surprising: “Blepharospasm was noted in only one patient in this series. He was one of the two CBS patients with photophobia and was pathologically confirmed to have CBD.” It seems that in our local support group blepharospasm is more common.
One note to the CBD folks: This article says that the term CBS (corticobasal syndrome) is used for the clinical entity while CBD (corticobasal degeneration) is used for the pathologic entity.
See below for some excerpts to this short article.
Robin
Here are some excerpts that may be of interest:
Introduction
“Progressive supranuclear palsy (PSP) and corticobasal de-
generation (CBD) are neurodegenerative disorders that display
some overlapping clinical features. The core clinical features
of PSP include vertical gaze palsy, axial more than appendic-
ular rigidity, and early postural instability. The core clinical
features of CBD include asymmetric appendicular rigidity and
cortical dysfunction including apraxia of limb. The term corti-
cobasal syndrome (CBS) has been applied to the clinical
entity, while CBD refers to the pathologic entity.”
“When the cardinal features of these two diseases are present
at disease onset, diagnosis may be relatively straightforward.
However, clinical features of these two diseases often overlap
and some of the cardinal features may not occur until later in
the disease course. These atypical disease presentations can
present a diagnostic dilemma, which may make it difficult for
clinicians to predict disease progression. Therefore, additional
clinical features that could distinguish PSP from CBD would be
helpful in clinical practice. Photophobia has been described in
PSP but not CBD to our knowledge. Visual hallucinations and
REM sleep behavior disorder (RBD) have not been emphasized
in either PSP or CBD.We conducted a study to determine
the frequency of photophobia, visual hallucinations, and RBD
in these two disease populations.”
Methods
“One movement disorders specialist (KAJ) evaluated all
patients with features suggestive of PSP and CBD from 2003
to 2006 at a single medical institution.”
“We questioned patients and their significant others regarding
the presence of photophobia, visual hallucinations, and RBD.
The question regarding photophobia emphasized discomfort
as a result of light exposure as opposed to frequent eye
closing or lack of eye opening. This distinction is important
since both blepharospasm and apraxia of eye opening can be
present in these disorders. Only well-formed visual hallucina-
tions that were spontaneous and not associated with medica-
tion use were considered. REM sleep behavior disorder was
considered present if the patient’s bed partner reported
abnormal limb movements during sleep that were disruptive or
injurious to either the bed partner or the patient.”
Results
“Ten patients had PSP, two with pathologic confirmation, and
11 patients had CBS, one with pathologic confirmation. The
median ages at disease onset in PSP and CBS were 66
(range 59-77) and 65 (range 49-91)…”
“Based on clinical criteria for PSP, four patients were clas-
sified as possible, four as probable, and two were definite
(i.e. pathologically confirmed).”
“Photophobia occurred in all 10 (100%) PSP patients vs 2
(18%) CBS patients. The mean time between when the
patient first reported photophobia and disease onset was
3.1 years.”
“Blepharospasm was noted in only one patient in this series.
He was one of the two CBS patients with photophobia and
was pathologically confirmed to have CBD.”
“Visual hallucinations occurred in 1 (5%) PSP patient and
RBD occurred in 1 (5%) CBS patient. The visual hallucina-
tions occurred in a PSP patient taking Levodopa/Carbidopa.
… The hallucinations continued despite reduction of the
Levodopa/Carbidoba and, unfortunately, the patient died
before further dose reductions could be made.”
“The CBS patient with RBD had symptoms consisting of
talking and performing exercising movements usually during
the first 1-2 h of sleep.”
Discussion
“The present study demonstrates a significant difference in
the frequency of photophobia in patients with PSP com-
pared to those with CBS. This result suggests that the
presence of photophobia may help clinicians to better dif-
ferentiate between PSP and CBS on a clinical basis, and
may be a helpful feature in predicting underlying pathology.”
“The pathophysiology of photophobia is not entirely under-
stood. Studies have pointed to the trigeminal nerve as one
necessary component for photophobia. … Other studies
have suggested a role of the optic nerve and its connec-
tions with the pretectal nuclei. Indeed, it may be an inter-
action of these two pathways that produce photophobia.
The corresponding subcortical location of the trigeminal
and optic nerve connections and typical subcortical loca-
tion of PSP pathology, such as the superior colliculi, may
explain the high incidence of photophobia found in our PSP
population. The subcortical location of PSP pathology con-
trasts with the more cortical location of pathology found in
CBD and may explain the relatively low frequency of photo-
phobia found in patients with CBS in our study. In fact, both
CBS patients with photophobia were two of only three CBS
patients with vertical gaze palsy suggesting pathological
involvement of brainstem nuclei in these two subjects.”
“Visual hallucinations and RBD were rare occurrences in
each population making them unhelpful in clinical differen-
tiation between PSP and CBS. The low occurrence of RBD
is not surprising since this clinical phenomenon has been
shown to be suggestive of underlying alpha-synuclein path-
ology, and both PSP and CBD are characterized by the
deposition of the microtubule associated protein tau
(MAPT) and not alpha-synuclein pathology.”
“Litvan et al. showed that the presence of gait abnormality,
bilateral bradykinesia, and moderate to severe vertical
supranuclear gaze palsy help to distinguish PSP from
CBS. Their study was based on pathologically confirmed
cases of these two diseases. Since our study is based
on clinical and/or pathologic criteria, we cannot conclude
that the presence of photophobia will definitely predict
pathologic confirmation of PSP. However, 15% of our
cases were pathologically confirmed and prior studies
have shown that more than 75% of clinically diagnosed
PSP patients have PSP pathology.”
“The results of our study suggest that patients suspected
to have PSP or CBD should be questioned regarding the
presence or absence of photophobia as part of routine
questioning. … In this study, we demonstrate for the first
time that the presence of photophobia may be an addi-
tional useful clinical feature to differentiate PSP from
CBD.”